dorsal/arxiv
View SchemaDynamics, Thermodynamics, and Time-Asymmetry
| Authors | Mario A. Castagnino, Edgerd Gunzig |
|---|---|
| Categories | |
| ArXiv ID | quant-ph/0008041 |
| URL | https://arxiv.org/abs/quant-ph/0008041 |
Abstract
064<p type="texpara" tag="Body Text" et="abstract" bin="clone" >There are two schools, or lines of thought, that try to unify the apparently divergent laws of dynamics and thermodynamics and to explain the observed time-asymmetry of the universe, and most of its sub-systems, in spite of the fact that these systems are driven by time-symmetric evolution equations. They will be called the coarse-graining and the fine-graining schools (even if these names describe only a part of their philosophy). Coarse-graining school obtains time-asymmetry via a projection of the state space on a space of ''relevant'' states. The corresponding projection of the primitive reversible evolution laws yields effective irreversible evolution laws for the relevant states. Fine-graining always use the same primitive reversible evolution laws. But these laws (in adequate extensions of the usual spaces where these laws are formulated) have a set of solutions $S$ that can be decompose in two subsets $S_{+\text{}}$ and $S_{-}$ of time asymmetric solutions. Choosing one of these two sets, as the arena to formulate the theory, time asymmetry is established. The aim of these lectures is to explain, in the simplest- self-contained, unbiased, and, honest way, the main characteristics of both schools and to point out the advantages and disadvantages of both formalism, in such a way that, the polemic between the schools, turns out to be explicit and organized in the mind of the reader (who will be considered the supreme judge to give the final verdict). 064<p type="texpara" tag="Body Text" et="abstract" bin="clone" >Some cosmological features of the theory will be also considered, mainly the problem of the low entropy initial state of the universe
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"abstract": "064\u003cp type=\"texpara\" tag=\"Body Text\" et=\"abstract\" bin=\"clone\" \u003eThere are two\nschools, or lines of thought, that try to unify the apparently divergent laws\nof dynamics and thermodynamics and to explain the observed time-asymmetry of\nthe universe, and most of its sub-systems, in spite of the fact that these\nsystems are driven by time-symmetric evolution equations. They will be called\nthe coarse-graining and the fine-graining schools (even if these names describe\nonly a part of their philosophy). Coarse-graining school obtains time-asymmetry\nvia a projection of the state space on a space of \u0027\u0027relevant\u0027\u0027 states. The\ncorresponding projection of the primitive reversible evolution laws yields\neffective irreversible evolution laws for the relevant states. Fine-graining\nalways use the same primitive reversible evolution laws. But these laws (in\nadequate extensions of the usual spaces where these laws are formulated) have a\nset of solutions $S$ that can be decompose in two subsets $S_{+\\text{}}$ and\n$S_{-}$ of time asymmetric solutions. Choosing one of these two sets, as the\narena to formulate the theory, time asymmetry is established. The aim of these\nlectures is to explain, in the simplest- self-contained, unbiased, and, honest\nway, the main characteristics of both schools and to point out the advantages\nand disadvantages of both formalism, in such a way that, the polemic between\nthe schools, turns out to be explicit and organized in the mind of the reader\n(who will be considered the supreme judge to give the final verdict).\n 064\u003cp type=\"texpara\" tag=\"Body Text\" et=\"abstract\" bin=\"clone\" \u003eSome\ncosmological features of the theory will be also considered, mainly the problem\nof the low entropy initial state of the universe",
"arxiv_id": "quant-ph/0008041",
"authors": [
"Mario A. Castagnino",
"Edgerd Gunzig"
],
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"title": "Dynamics, Thermodynamics, and Time-Asymmetry",
"url": "https://arxiv.org/abs/quant-ph/0008041"
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