Results 11 to 20 of about 12,793 (259)

Wormholes and the thermodynamic arrow of time

open access: yesPhysical Review Research, 2020
In classical thermodynamics, heat cannot spontaneously pass from a colder system to a hotter system, which is called the thermodynamic arrow of time. However, if the initial states are entangled, the direction of the thermodynamic arrow of time may not ...
Zhuo-Yu Xian, Long Zhao
doaj   +1 more source

Gravitational Entropy and Inflation

open access: yesEntropy, 2013
The main topic of this paper is a description of the generation of entropy at the end of the inflationary era. As a generalization of the present standard model of the Universe dominated by pressureless dust and a Lorentz invariant vacuum energy (LIVE ...
Øystein Elgarøy, Øyvind Grøn
doaj   +1 more source

How many universes are necessary for an ice cream to melt? [PDF]

open access: yesSerbian Astronomical Journal, 2003
We investigate a quantitative consequence of the Acausal-Anthropic approach to solving the long-standing puzzle of the thermo dynamical arrow of time.
Ćirković Milan M.
doaj   +1 more source

Entropy production and the arrow of time

open access: yesNew Journal of Physics, 2009
15 pages, no ...
Parrondo, J. M. R.   +2 more
openaire   +3 more sources

On Quantum Entropy

open access: yesEntropy, 2022
Quantum physics, despite its intrinsically probabilistic nature, lacks a definition of entropy fully accounting for the randomness of a quantum state. For example, von Neumann entropy quantifies only the incomplete specification of a quantum state and ...
Davi Geiger, Zvi M. Kedem
doaj   +1 more source

Gravitational Entropy and the Second Law of Thermodynamics

open access: yesEntropy, 2015
The spontaneous violation of Lorentz and diffeomorphism invariance in a phase near the big bang lowers the entropy, allowing for an arrow of time and the second law of thermodynamics. The spontaneous symmetry breaking leads to
John W. Moffat
doaj   +1 more source

Entropy and Cosmological Arrows of Time

open access: yes, 2021
Deutsch and Aguirre have recently shown that the solutions of certain dynamical systems typically contain a point of minimum size that they identify as an entropy minimum and from which the size and entropy increase to infinity in both directions of time.
openaire   +2 more sources

Cosmological Time, Entropy and Infinity

open access: yesEntropy, 2017
Time is a parameter playing a central role in our most fundamental modelling of natural laws. Relativity theory shows that the comparison of times measured by different clocks depends on their relative motion and on the strength of the gravitational ...
Clémentine Hauret   +2 more
doaj   +1 more source

Multi-Objective Constructal Design for Square Heat-Generation Body with “Arrow-Shaped” High-Thermal-Conductivity Channel

open access: yesEnergies, 2022
Based on the square heat-generation body (HGB) with “arrow-shaped” high-thermal-conductivity channel (HTCC) model established in the previous literature, we performed multi-objective optimization (MOO) with maximum temperature difference (MTD ...
Hongwei Zhu   +4 more
doaj   +1 more source

Irreversibility of time in general relativity [PDF]

open access: yesИзвестия Саратовского университета. Новая серия: Физика, 2022
Background and Objectives: The equations of classical dynamics of particles and waves admit solutions with the reverse flow of time. Therefore, it is generally assumed that classical dynamics does not reflect the irreversibility of time.
Tsoy, Valery Ivanovich
doaj   +1 more source

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