Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:1211.1739

EPR measurement and the origin of cosmic density fluctuations

Masahiro Morikawa

Published Nov 8, 2012• 0 citations
arXivHTMLPDF

Abstract

We explore consistent application of quantum mechanics to the objects in the Universe and in laboratories. The measurement dynamics in quantum mechanics is modeled as a physical process of spontaneous symmetry breaking (SSB) which is described by the generalized effective action method. A violation of the Bell inequality is observed in this model and the generation of the density fluctuations in the early Universe is described as the SSB process of the spatially translational symmetry.

DOI
10.48550/arxiv.1211.1739

Related papers

EPR measurement and the origin of cosmic density fluctuations

Masahiro Morikawa

We explore consistent application of quantum mechanics to the objects in the Universe and in laboratories. The measurement dynamics in quantum mechanics is modeled as a physical process of spontaneous symmetry breaking (SSB) which is described by the generalized effective action method. A violation of the Bell inequality is observed in this model and the generation of the density fluctuations in the early Universe is described as the SSB process of the spatially translational symmetry.

EPJ Web of Conferences•Jan 1, 2014•0 citations

Bell Inequality and Its Application to Cosmology

Sugumi Kanno, Jiro Soda

One of the cornerstones of inflationary cosmology is that primordial density fluctuations have a quantum mechanical origin. However, most physicists consider that such quantum mechanical effects disappear in CMB data due to decoherence. In this conference report, we show that the violation of Bell inequalities in an initial state of our universe increases exponentially with the number of modes to measure in inflation. This indicates that some evidence that our universe has a quantum mechanical origin may survive in CMB data, even if quantum entanglement decays exponentially afterward due to decoherence.

Galaxies•Dec 12, 2017•9 citations

Cosmology, initial conditions, and the measurement problem

David Layzer

The assumption that a complete description of an early state of the universe does not privilege any position or direction in space leads to a unified account of probability in cosmology, macroscopic physics, and quantum mechanics. Such a description has a statistical character. Deterministic laws link it to statistical descriptions of the cosmic medium at later times, and because these laws do not privilege any position or direction in space, the same must be true of these descriptions. If the universe is infinite, we can identify the probability that the energy density at a particular instant and a particular point in space (relative to a system of spacetime coordinates in which the postulated spatial symmetries are manifest) lies in a given range with the fractional volume occupied by points where the energy density lies in this range; and similarly with all other probabilities that figure in the statistical description. The probabilities that figure in a complete description of the cosmic medium at any given moment thus have an exact and objective physical interpretation. The statistical entropy and the information associated with each cosmological probability distribution are likewise objective properties of the universe, defined in terms of relative frequencies or spatial averages.

arXiv:1008.1229•Aug 6, 2010•2 citations

The universe from a single particle. Part II

Michael Hartley Freedman, Modjtaba Shokrian Zini

Abstract We continue to explore, in the context of a toy model, the hypothesis that the interacting universe we see around us could result from single particle (undergraduate) quantum mechanics via a novel spontaneous symmetry breaking (SSB) acting at the level of probability distributions on Hamiltonians (rather than on states as is familiar from both Ginzburg-Landau superconductivity and the Higgs mechanism). In an earlier paper [1] we saw qubit structure emerge spontaneously on ℂ4 and ℂ8, and in this work we see ℂ6 spontaneously decomposing as ℂ2 ⊗ ℂ3 and very curiously ℂ5 (and ℂ7) splitting off one (one or three) directions and then factoring. This evidence provides additional support for the broad hypothesis: Nature will seek out tensor decompositions where none are present. We consider how this finding may form a basis for the origins of interaction and ask if it can be related to established foundational discussions such as string theory.

arXiv:2108.12709•Journal of High Energy Physics•Oct 1, 2021•5 citations

Was the Early Universe Quantum? Falsifying Classical Stochastic Inflation

Veronica Sanz B

Inflationary cosmology successfully accounts for the observed properties of primordial fluctuations using quantum field theory in an expanding background. However, the quantum nature of these fluctuations has not been experimentally established, since classical stochastic models could reproduce the observed two-point statistics by construction. Existing approaches to testing primordial quantumness focus primarily on Bell inequalities, which provide a sharp conceptual criterion but are difficult to implement with cosmological observables. In this work we adopt a falsification-based approach. We define a precise classical hypothesis for the origin of primordial perturbations (local stochastic fields admitting a positive probability distribution) and identify inequality constraints that must be satisfied within this class. We show how violations of these classicality inequalities can be probed using realistic cosmological observables, without invoking Bell tests or non-commuting measurement settings. We further identify symmetry-protected spectator sectors in which quantum coherence is parametrically preserved during inflation, allowing violations of observable magnitude to survive decoherence. Our results show that large-scale structure and future 21 cm surveys provide a viable and quantitative route to falsifying classical stochastic descriptions of primordial fluctuations.

arXiv:2601.13053•Jan 19, 2026•0 citations

Transient Quantum Processes toward Classical Structure - Through squeezed state and coherent state -

Masahiro Morikawa

Many quantum systems in various fields, a classical signal spontaneously appears without any specific operations/measurements. For example, the initiation of the spontaneous symmetry breaking, the appearance of the off-diagonal long-range order in the Bose-Einstein condensate, the transient process of the quantum fluctuations in the early Universe, etc.  We are interested in the basic principle of these transient processes in quantum systems which shows classical signal spontaneously. We start our observation that some instability often promotes the squeezing of the original quantum system. This is usually interpreted as the particle production or the Bogoliubov shift of the vacuum. At this stage, everything is Unitary and reversible. For example, Hawking radiation around the Black Hole, the thermal state associated with the accelerated observer (Unruh effect), and the particle production in the expanding universe, etc. are all in this category. By using the Schwinger-Keldysh in-in formalism of quantum field theory, we find that these squeezed states are associated with non-dissipative classical fluctuations. We call them dry-noise. Then applying the generalized effective action method and deriving the Langevin equation, we find that these dry-noise triggers, through nonlinear interactions, to develop the coherent state which can be classical if sufficiently developed. This is the origin of the classical signal in the full quantum systems. The appearance of the squeezed state through the tachyonic instability and the development of the coherent state through the nonlinearity seem to be a general transient process that a classical signal spontaneously develops. These states appear more generally not only in the quantum optics. We finally show that this formalism is widely applicable; initiation dynamics of the spontaneous symmetry breaking in quantum systems such as BEC, Black hole entropy, Unruh detectors, and quantum cosmology. These analyses may give some implications on the origin of the irreversibility associated with the transition from quantum to classical. The detail description is in arxiv.org/abs/1810.11293 and the references therein.

StatPhys 27 Main Conference•Apr 18, 2019•0 citations
We explore consistent application of quantum mechanics to the objects in the Universe and in laboratories. The measurement dynamics in quantum mechanics is modeled as a physical process of spontaneous symmetry breaking (SSB) which is described by the generalized effective action method. A violation of the Bell inequality is observed in this model and the generation of the density fluctuations in the early Universe is described as the SSB process of the spatially translational symmetry.
One of the cornerstones of inflationary cosmology is that primordial density fluctuations have a quantum mechanical origin. However, most physicists consider that such quantum mechanical effects disappear in CMB data due to decoherence. In this conference report, we show that the violation of Bell inequalities in an initial state of our universe increases exponentially with the number of modes to measure in inflation. This indicates that some evidence that our universe has a quantum mechanical origin may survive in CMB data, even if quantum entanglement decays exponentially afterward due to decoherence.
The assumption that a complete description of an early state of the universe does not privilege any position or direction in space leads to a unified account of probability in cosmology, macroscopic physics, and quantum mechanics. Such a description has a statistical character. Deterministic laws link it to statistical descriptions of the cosmic medium at later times, and because these laws do not privilege any position or direction in space, the same must be true of these descriptions. If the universe is infinite, we can identify the probability that the energy density at a particular instant and a particular point in space (relative to a system of spacetime coordinates in which the postulated spatial symmetries are manifest) lies in a given range with the fractional volume occupied by points where the energy density lies in this range; and similarly with all other probabilities that figure in the statistical description. The probabilities that figure in a complete description of the cosmic medium at any given moment thus have an exact and objective physical interpretation. The statistical entropy and the information associated with each cosmological probability distribution are likewise objective properties of the universe, defined in terms of relative frequencies or spatial averages.
Abstract We continue to explore, in the context of a toy model, the hypothesis that the interacting universe we see around us could result from single particle (undergraduate) quantum mechanics via a novel spontaneous symmetry breaking (SSB) acting at the level of probability distributions on Hamiltonians (rather than on states as is familiar from both Ginzburg-Landau superconductivity and the Higgs mechanism). In an earlier paper [1] we saw qubit structure emerge spontaneously on ℂ4 and ℂ8, and in this work we see ℂ6 spontaneously decomposing as ℂ2 ⊗ ℂ3 and very curiously ℂ5 (and ℂ7) splitting off one (one or three) directions and then factoring. This evidence provides additional support for the broad hypothesis: Nature will seek out tensor decompositions where none are present. We consider how this finding may form a basis for the origins of interaction and ask if it can be related to established foundational discussions such as string theory.
Inflationary cosmology successfully accounts for the observed properties of primordial fluctuations using quantum field theory in an expanding background. However, the quantum nature of these fluctuations has not been experimentally established, since classical stochastic models could reproduce the observed two-point statistics by construction. Existing approaches to testing primordial quantumness focus primarily on Bell inequalities, which provide a sharp conceptual criterion but are difficult to implement with cosmological observables. In this work we adopt a falsification-based approach. We define a precise classical hypothesis for the origin of primordial perturbations (local stochastic fields admitting a positive probability distribution) and identify inequality constraints that must be satisfied within this class. We show how violations of these classicality inequalities can be probed using realistic cosmological observables, without invoking Bell tests or non-commuting measurement settings. We further identify symmetry-protected spectator sectors in which quantum coherence is parametrically preserved during inflation, allowing violations of observable magnitude to survive decoherence. Our results show that large-scale structure and future 21 cm surveys provide a viable and quantitative route to falsifying classical stochastic descriptions of primordial fluctuations.
Many quantum systems in various fields, a classical signal spontaneously appears without any specific operations/measurements. For example, the initiation of the spontaneous symmetry breaking, the appearance of the off-diagonal long-range order in the Bose-Einstein condensate, the transient process of the quantum fluctuations in the early Universe, etc.  We are interested in the basic principle of these transient processes in quantum systems which shows classical signal spontaneously. We start our observation that some instability often promotes the squeezing of the original quantum system. This is usually interpreted as the particle production or the Bogoliubov shift of the vacuum. At this stage, everything is Unitary and reversible. For example, Hawking radiation around the Black Hole, the thermal state associated with the accelerated observer (Unruh effect), and the particle production in the expanding universe, etc. are all in this category. By using the Schwinger-Keldysh in-in formalism of quantum field theory, we find that these squeezed states are associated with non-dissipative classical fluctuations. We call them dry-noise. Then applying the generalized effective action method and deriving the Langevin equation, we find that these dry-noise triggers, through nonlinear interactions, to develop the coherent state which can be classical if sufficiently developed. This is the origin of the classical signal in the full quantum systems. The appearance of the squeezed state through the tachyonic instability and the development of the coherent state through the nonlinearity seem to be a general transient process that a classical signal spontaneously develops. These states appear more generally not only in the quantum optics. We finally show that this formalism is widely applicable; initiation dynamics of the spontaneous symmetry breaking in quantum systems such as BEC, Black hole entropy, Unruh detectors, and quantum cosmology. These analyses may give some implications on the origin of the irreversibility associated with the transition from quantum to classical. The detail description is in arxiv.org/abs/1810.11293 and the references therein.