Jeans’s criterion using various cosmological terms
Author
Source
Issue
Vol. 1, Issue 1 (30 Sep. 2011), pp.1-21, 21 p.
Publisher
Amgad Society for Developing the Community and Protecting the Environment
Publication Date
2011-09-30
Country of Publication
Egypt
No. of Pages
21
Main Subjects
Abstract EN
Jeans’s criterion concerning the gravitational instability of a quasi-infinite homogeneous medium is revisited.
The original erroneous derivation is improved by considering the gravitational potential around an extremum.
However, it is shown that the domain of valid approximation is about as large as the instability region, still leaving doubts about the correctness of the criterion.
A derivation using a cosmological constant is obtained which avoids the inconsistency and recovers Jeans’s criterion to a very good approximation.
However, other problems arise.
Moreover, when we use a sensible bilinear cosmological term then a kind of standard instability length results, not the Jeans’s wavelength.
Using a cosmological term quadratic in the density leads again to a good approximation of Jeans’s criterion.
Hence the precise form of the cosmological term turns out to be quite relevant.
The underlying physical mechanism of the instability is explained, confirming theright order of the Jeans’s instability wavelength and Jeans’s mass.
The stability analysis of an infinite gravitational cylinder and of a plane-parallel medium support Jeans’s result too.
Some confirmations on the basis of celestial bodies (Earth, Sun, galaxy, cosmic tessellation) are briefly considered, including the effect of scaling.
This leads to another interpretation of Jeans’s wavelength: it is about (in fact slightly larger than) the diameter of celestial bodies in equilibrium and thus it expresses rather the stability of the body.
The cosmic entropy concept is discussed in the light of Jeans’s criterion.
American Psychological Association (APA)
Callebaut, Dirk K.. 2011. Jeans’s criterion using various cosmological terms. Alexandria Journal of Physics،Vol. 1, no. 1, pp.1-21.
https://search.emarefa.net/detail/BIM-786592
Modern Language Association (MLA)
Callebaut, Dirk K.. Jeans’s criterion using various cosmological terms. Alexandria Journal of Physics Vol. 1, no. 1 (Sep. 2011), pp.1-21.
https://search.emarefa.net/detail/BIM-786592
American Medical Association (AMA)
Callebaut, Dirk K.. Jeans’s criterion using various cosmological terms. Alexandria Journal of Physics. 2011. Vol. 1, no. 1, pp.1-21.
https://search.emarefa.net/detail/BIM-786592
Data Type
Journal Articles
Language
English
Notes
Includes bibliographical references : p. 20-21
Record ID
BIM-786592