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Related papers: Time evolution as refining, coarse graining and en…

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After a brief review of spin networks and their interpretation as wave functions for the (space) geometry, we discuss the renormalisation of the area operator in loop quantum gravity. In such a background independent framework, we propose…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Etera R. Livine , Daniel R. Terno

We introduce a framework for non-linear time evolution in quantum mechanics as a natural non-linear generalization of the Schrodinger equation. Within our framework, we derive simple toy models of dynamical geometry on finite graphs. Along…

High Energy Physics - Theory · Physics 2017-09-06 Dushyant Kumar

On the path towards quantum gravity, we find friction between temporal relations in quantum mechanics (QM) (where they are fixed and field-independent), and in general relativity (where they are field-dependent and dynamic). This paper aims…

General Relativity and Quantum Cosmology · Physics 2017-11-28 Henrique Gomes

We introduce a general framework for deriving effective dynamics from arbitrary time-dependent generators, based on a systematic operator cumulant expansion. Unlike traditional approaches, which typically assume periodic or adiabatic…

Mathematical Physics · Physics 2025-10-02 Leon Bello , Tal Rubin , Wentao Fan , Nathaniel Fisch , Hakan Türeci

The Renormalization Group encodes three concepts that could be key to accelerate progress in quantum gravity. First, it provides a micro-macro connection that could connect microscopic spacetime physics to phenomenology at observationally…

General Relativity and Quantum Cosmology · Physics 2021-03-29 Astrid Eichhorn , Benjamin Bahr , Antonio D. Pereira

We investigate time operators in the context of quantum time crystals in ring systems. A generalized commutation relation called the generalized weak Weyl relation is used to derive a class of self-adjoint time operators for ring systems…

Quantum Physics · Physics 2019-06-25 K. Nakatsugawa , T. Fujii , A. Saxena , S. Tanda

Understanding the emergence of macroscopic irreversible hydrodynamics from the reversible unitary dynamics of isolated quantum many-body systems remains a fundamental challenge. Conventional approaches often force spin density dynamics into…

Quantum Physics · Physics 2026-05-08 Seiki Saito

A commonly adopted relational account of time evolution in generally-covariant systems, and more specifically in quantum cosmology, is argued to be unsatisfactory, insofar as it describes evolution relative to observed readings of a clock…

General Relativity and Quantum Cosmology · Physics 2011-03-10 Ian D. Lawrie

Familiar textbook quantum mechanics assumes a fixed background spacetime to define states on spacelike surfaces and their unitary evolution between them. Quantum theory has changed as our conceptions of space and time have evolved. But…

General Relativity and Quantum Cosmology · Physics 2008-06-09 James B. Hartle

064<p type="texpara" tag="Body Text" et="abstract" bin="clone" >There are two schools, or lines of thought, that try to unify the apparently divergent laws of dynamics and thermodynamics and to explain the observed time-asymmetry of the…

Quantum Physics · Physics 2019-08-17 Mario A. Castagnino , Edgerd Gunzig

Each scheme of state reconstruction comes down to parametrize the state of a quantum system by expectation values or probabilities directly measurable in an experiment. It is argued that the time evolution of these quantities provides an…

Quantum Physics · Physics 2014-11-18 Stefan Weigert

We characterize good clocks, which are naturally subject to fluctuations, in statistical terms. We also obtain the master equation that governs the evolution of quantum systems according to these clocks and find its general solution. This…

Quantum Physics · Physics 2009-10-31 Inigo L. Egusquiza , Luis J. Garay , Jose M. Raya

In this paper I offer an introduction to group field theory (GFT) and to some of the issues affecting the foundations of this approach to quantum gravity. I first introduce covariant GFT as the theory that one obtains by interpreting the…

General Relativity and Quantum Cosmology · Physics 2024-06-14 Álvaro Mozota Frauca

The fundamental dynamics of quantum particles is neutral with respect to the arrow of time. And yet, our experiments are not: we observe quantum systems evolving from the past to the future, but not the other way round. A fundamental…

Quantum Physics · Physics 2022-11-01 Giulio Chiribella , Zixuan Liu

We link the notion causality with the orientation of the 2-complex on which spin foam models are based. We show that all current spin foam models are orientation-independent, pointing out the mathematical structure behind this independence.…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Daniele Oriti

The Entropic Dynamics reconstruction of quantum mechanics is extended to quantum field theory in curved space-time. The Entropic Dynamics framework, which derives quantum theory as an application of the method of maximum entropy, is…

General Relativity and Quantum Cosmology · Physics 2020-01-08 Selman Ipek , Mohammad Abedi , Ariel Caticha

In loop quantum gravity, partitioning graph introduces boundaries and entanglement between spin sub-networks, reflecting non-local degrees of freedom and correlation amongst spatial regions. This gives rise to the view of coarse-graining,…

High Energy Physics - Theory · Physics 2022-05-24 Qian Chen

Given a fine-scale physical theory characterized by an evolutionary system of equations and a set of quantities, defined from the variables of the fine theory, that serve as a coarse representation of the fine scale phenomena, a systematic…

Statistical Mechanics · Physics 2007-05-23 Amit Acharya

The quantum mechanical time-evolution is studied for a particle under the influence of an explicitly time-dependent rotating potential. We discuss the existence of the propagator and we show that in the limit of rapid rotation it converges…

Mathematical Physics · Physics 2007-05-23 Volker Enss , Vadim Kostrykin , Robert Schrader

The center of mass motion of trapped ions and neutral atoms is suitable for approximation by a time-dependent driven quantum harmonic oscillator whose frequency and driving strength may be controlled with high precision. We show the time…

Quantum Physics · Physics 2024-03-25 E. García Herrera , F. Torres-Leal , B. M. Rodríguez-Lara