Chen, Eddy Keming (2018) Quantum Mechanics in a Time-Asymmetric Universe: On the Nature of the Initial Quantum State. [Preprint]

Preview

Text IPH3.pdf - Submitted Version Download (281kB) | Preview

Abstract

In a quantum universe with a strong arrow of time, we postulate a low-entropy boundary condition (the Past Hypothesis) to account for the temporal asymmetry. In this paper, I show that the Past Hypothesis also contains enough information to simplify the quantum ontology and define a unique initial condition in such a world. First, I introduce Density Matrix Realism, the thesis that the quantum universe is described by a fundamental density matrix (a mixed state) that represents something objective. This stands in sharp contrast to Wave Function Realism, the thesis that the quantum universe is described by a wave function (a pure state) that represents something objective. Second, I suggest that the Past Hypothesis is sufficient to determine a unique and simple density matrix. This is achieved by what I call the Initial Projection Hypothesis: the initial density matrix of the universe is the normalized projection onto the special low-dimensional Hilbert space. Third, because the initial quantum state is unique and simple, we have a strong case for the \emph{Nomological Thesis}: the initial quantum state of the universe is on a par with laws of nature. This new package of ideas has several interesting implications, including on the harmony between statistical mechanics and quantum mechanics, the dynamic unity of the universe and the subsystems, and the alleged conflict between Humean supervenience and quantum entanglement.

---

Export/Citation:

EndNote | BibTeX | Dublin Core | ASCII/Text Citation (Chicago) | HTML Citation | OpenURL

Social Networking:

Share |

---

Item Type:	Preprint
Creators:	Creators Email ORCID Chen, Eddy Keming eddy.chen@rutgers.edu
Keywords:	time’s arrow, Past Hypothesis, Statistical Postulate, reduction, typicality, foundations of probability, quantum statistical mechanics, wave function realism, quantum ontology, density matrix, Weyl Curvature Hypothesis, Humean Supervenience
Subjects:	General Issues > Determinism/Indeterminism General Issues > Laws of Nature Specific Sciences > Physics > Quantum Mechanics General Issues > Realism/Anti-realism Specific Sciences > Physics > Statistical Mechanics/Thermodynamics
Depositing User:	Dr. Eddy Keming Chen
Date Deposited:	09 Jun 2018 18:44
Last Modified:	09 Jun 2018 18:44
Item ID:	14764
Subjects:	General Issues > Determinism/Indeterminism General Issues > Laws of Nature Specific Sciences > Physics > Quantum Mechanics General Issues > Realism/Anti-realism Specific Sciences > Physics > Statistical Mechanics/Thermodynamics
Date:	8 June 2018
URI:	https://philsci-archive.pitt.edu/id/eprint/14764

Available Versions of this Item

• Time's Arrow in a Quantum Universe I: On the Simplicity and Uniqueness of the Initial Quantum State. (deposited 05 Dec 2017 18:18)
  • Time's Arrow in a Quantum Universe I: On the Simplicity and Uniqueness of the Initial Quantum State. (deposited 14 Dec 2017 03:35)
    • Quantum Mechanics in a Time-Asymmetric Universe: On the Nature of the Initial Quantum State. (deposited 09 Jun 2018 18:44) [Currently Displayed]
      • Quantum Mechanics in a Time-Asymmetric Universe: On the Nature of the Initial Quantum State. (deposited 30 Sep 2018 15:27)
        • Quantum Mechanics in a Time-Asymmetric Universe: On the Nature of the Initial Quantum State. (deposited 11 Mar 2022 02:14)

Monthly Views for the past 3 years

Monthly Downloads for the past 3 years

Plum Analytics

Actions (login required)

View Item