English
Related papers

Related papers: How classical is the quantum universe?

200 papers

We give a partial answer to the question whether the Schrodinger equation can be derived from the Newtonian mechanics of a particle in a potential subject to a random force. We show that the fluctuations around the classical motion of a one…

Quantum Physics · Physics 2021-02-24 Can Gokler

Classical and quantum physics represent two distinct theories; however, quantum physics is regarded as the more fundamental of the two. It is posited that classical mechanics should arise from quantum mechanics under certain limiting…

Quantum Physics · Physics 2026-01-21 Abdul Rahaman Shaikh , Tabish Qureshi

Building upon a recent analysis of the measurement process in Hamiltonian mechanics, this article investigates the Bayesian epistemology of classical physics -- the landscape of accessible probability distributions over phase space. I prove…

Statistical Mechanics · Physics 2025-04-01 David Theurel

The most striking observable feature of our indeterministic quantum universe is the wide range of time, place, and scale on which the deterministic laws of classical physics hold to an excellent approximation. This essay describes how this…

Quantum Physics · Physics 2011-05-23 James B. Hartle

Ever since the advent of quantum mechanics, it has been clear that the atoms composing matter do not obey Newton's laws. Instead, their behavior is described by the Schroedinger equation. Surprisingly though, until recently, no clear…

Quantum Physics · Physics 2007-05-23 Tanmoy Bhattacharya , Salman Habib , Kurt Jacobs

Quantum theory demands that, in contrast to classical physics, not all properties can be simultaneously well defined. The Heisenberg Uncertainty Principle is a manifestation of this fact. Another important corollary arises that there can be…

It is shown that Schroedinger's equation may be derived from three postulates. The first is a kind of statistical metamorphosis of classical mechanics, a set of two relations which are obtained from the canonical equations of particle…

Quantum Physics · Physics 2011-03-09 U. Klein

How much of the uncertainty in predicting measurement outcomes for non-commuting quantum observables is genuinely quantum mechanical? We provide a natural decomposition of the total entropic uncertainty of two non-commuting observables into…

Quantum Physics · Physics 2014-05-01 Kamil Korzekwa , Matteo Lostaglio , David Jennings , Terry Rudolph

The Schr\"odinger equation is shown to be equivalent to a constrained Liouville equation under the assumption that phase space is extended to Grassmann algebra valued variables. For onedimensional systems, the underlying Hamiltonian…

High Energy Physics - Theory · Physics 2009-11-10 H. -T. Elze

We propose that the Schrodinger equation results from applying the classical wave equation to describe the physical system in which subatomic particles play random motion, thereby leading to quantum mechanics. The physical reality described…

General Physics · Physics 2022-04-18 Xue-Shu Zhao , Yu-Ru Ge , Xin Zhao , Hong Zhao

The introduction of nonlinearities in the Schr\"odinger equation has been considered in the literature as an effective manner to describe the action of external environments or mean fields. Here, in particular, we explore the nonlinear…

Quantum Physics · Physics 2024-03-08 David Navia , Ángel S. Sanz

Is quantum mechanics about 'states'? Or is it basically another kind of probability theory? It is argued that the elementary formalism of quantum mechanics operates as a well-justified alternative to 'classical' instantiations of a…

Quantum Physics · Physics 2014-10-28 Jean-Michel Delhotel

The Schroedinger- and Klein-Gordon equations are directly derived from classical Lagrangians. The only inputs are given by the discreteness of energy (E=hbar.w) and momentum (p=hbar.k), respectively, as well as the assumed existence of a…

Quantum Physics · Physics 2007-05-23 Gerhard Groessing

The formalism of classical and quantum mechanics on phase space leads to symplectic and Heisenberg group representations, respectively. The Wigner functions give a representation of the quantum system using classical variables. The…

Quantum Physics · Physics 2007-05-23 Ajay Patwardhan

A canonical quantisation of the coordinates of the spacetime within the general relativity theory is proposed. This quantisation will depend on the observer but it provides an interesting perspective on the problem of relating the…

General Relativity and Quantum Cosmology · Physics 2019-01-17 Iñaki Garay , Salvador Robles-Pérez

Classical limits of quantum systems are shown to lead to different conceptions of spaces different from the classical one underlying the process of quantization of such systems. The accent is put in situations where traces of…

Quantum Physics · Physics 2022-07-22 Thierry Paul

We consider classical theories described by Hamiltonians $H(p,q)$ that have a non-degenerate minimum at the point where generalized momenta $p$ and generalized coordinates $q$ vanish. We assume that the sum of squares of generalized momenta…

Quantum Physics · Physics 2025-04-21 Albert Schwarz

Recently we showed that the postulated diffeomorphic equivalence of states implies quantum mechanics. This approach takes the canonical variables to be dependent by the relation p=\partial_q S_0 and exploits a basic GL(2,C)-symmetry which…

High Energy Physics - Theory · Physics 2009-10-30 Alon E. Faraggi , Marco Matone

Heisenberg's uncertainty principle is often cited as an example of a "purely quantum" relation with no analogue in the classical limit where $\hbar \to 0$. However, this formulation of the classical limit is problematic for many reasons,…

Quantum Physics · Physics 2021-02-23 Viola Gattus , Sotirios Karamitsos

A new derivation is given of the known generalized position-momentum uncertainty relation, which takes into account gravity. The problem of two massive particles, the relative motion of which is described by the Schroedinger equation, is…

Quantum Physics · Physics 2020-04-22 V. E. Kuzmichev , V. V. Kuzmichev