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Following the idea of a field quantization of gravity as realized in group field theory, we construct a minisuperspace model where the wavefunction of canonical quantum cosmology (either Wheeler-DeWitt or loop quantum cosmology) is promoted…

General Relativity and Quantum Cosmology · Physics 2012-05-02 Gianluca Calcagni , Steffen Gielen , Daniele Oriti

We solve time-sliced path integrals of one-dimensional Coulomb system in an exact manner. In formulating path integrals, we make use of the Duru-Kleinert transformation with Fujikawa's gauge theoretical technique. Feynman kernels in the…

High Energy Physics - Theory · Physics 2009-03-24 Seiji Sakoda

We develop a path integral representation for the dynamics of quantum systems with a finite-dimensional Hilbert space, formulated entirely within a discrete phase space. Starting from the discrete Wigner function defined on $\mathbb{Z}_d…

Quantum Physics · Physics 2026-04-23 Leonardo A. Pachon , Andres F. Gomez

It is apparent to anyone who thinks about it that, to a large degree, the basic concepts of Newtonian physics are quite intuitive, but quantum mechanics is not. My purpose in this talk is to introduce you to a new, much more intuitive way…

Quantum Physics · Physics 2009-02-12 Marvin Weinstein

By carefully analyzing the relations between operator methods and the discretized and continuum path integral formulations of quantum-mechanical systems, we have found the correct Feynman rules for one-dimensional path integrals in curved…

High Energy Physics - Theory · Physics 2009-10-28 Jan de Boer , Bas Peeters , Kostas Skenderis , Peter van Nieuwenhuizen

Effective equations often provide powerful tools to develop a systematic understanding of detailed properties of a quantum system. This is especially helpful in quantum cosmology where several conceptual and technical difficulties…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Martin Bojowald , Hector Hernandez , Aureliano Skirzewski

A crucial problem in quantum cosmology is a careful analysis of the one-loop semiclassical approximation for the wave function of the universe, after an appropriate choice of mixed boundary conditions. The results for Euclidean quantum…

High Energy Physics - Theory · Physics 2007-05-23 Giampiero Esposito , Alexander Yu. Kamenshchik

The Feynman path integral representation of quantum theory is used in a non--parametric Bayesian approach to determine quantum potentials from measurements on a canonical ensemble. This representation allows to study explicitly the…

Quantum Physics · Physics 2007-05-23 J. C. Lemm , J. Uhlig , A. Weiguny

We give an introduction into quantum cosmology with emphasis on its conceptual parts. After a general motivation we review the formalism of canonical quantum gravity on which discussions of quantum cosmology are usually based. We then…

General Relativity and Quantum Cosmology · Physics 2022-09-23 Claus Kiefer , Barbara Sandhoefer

Quantum cosmology is studied within the framework of the minimal quantum gravity theory proposed by Ho\v{r}ava. For this purpose we choose the Kantowski-Sachs (KS) model and construct the corresponding Wheeler-DeWitt equation. We study the…

General Relativity and Quantum Cosmology · Physics 2013-05-31 O. Obregón , J. A. Preciado

For many years, the most active area of quantum cosmology has been the issue of choosing boundary conditions for the wave function of a universe. Recently, loop quantum cosmology, which is obtained from loop quantum gravity, has shed new…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Martin Bojowald , Kevin Vandersloot

We study the quantum cosmology of a quadratic $f(R)$ theory with a FRW metric, via one of its equivalent Horndeski type actions, where the dynamics of the scalar field is induced. The classical equations of motion and the Weeler-deWitt…

General Relativity and Quantum Cosmology · Physics 2017-06-22 V. Vázquez-Báez , C. Ramírez

In various background independent approaches, quantum gravity is defined in terms of a field propagation kernel: a sum over paths interpreted as a transition amplitude between 3-geometries, expected to project quantum states of the geometry…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Federico Mattei , Carlo Rovelli , Simone Speziale , Massimo Testa

We consider Feynman's path integral approach to quantum mechanics with a noncommutativity in position and momentum sectors of the phase space. We show that a quantum-mechanical system with this kind of noncommutativity is equivalent to the…

High Energy Physics - Theory · Physics 2007-05-23 Branko Dragovich , Zoran Rakic

Both Bohmian mechanics, a version of quantum mechanics with trajectories, and Feynman's path integral formalism have something to do with particle paths in space and time. The question thus arises how the two ideas relate to each other. In…

Quantum Physics · Physics 2009-11-11 Roderich Tumulka

In this paper we provide the DeWitt propagator and its wave function in quantum cosmology using the path integral formulation of quantum gravity. The DeWitt boundary condition is introduced as a way to avoid the Big Bang singularity by…

General Relativity and Quantum Cosmology · Physics 2024-02-05 Hiroki Matsui

Efforts to give an improved mathematical meaning to Feynman's path integral formulation of quantum mechanics started soon after its introduction and continue to this day. In the present paper, one common thread of development is followed…

Quantum Physics · Physics 2016-11-23 John R. Klauder

Feynman's path integrals provide a hidden variable description of quantum mechanics (and quantum field theories). The expectation values defined through path integrals obey Bell's inequalities in Euclidean time, but not in Minkowski time.…

High Energy Physics - Theory · Physics 2007-05-23 Apoorva Patel

In the quantization of simple cosmological models (minisuperspace models) described by the Wheeler-DeWitt equation, an important step is the construction, from the wave function, of a probability distribution answering various questions of…

General Relativity and Quantum Cosmology · Physics 2010-04-30 J. J. Halliwell

The mathematical similarities between non-relativistic wavefunction propagation in quantum mechanics and image propagation in scalar diffraction theory are used to develop a novel understanding of time and paths through spacetime as a…

Quantum Physics · Physics 2021-03-08 Sky Nelson-Isaacs