BransDicke Cosmology and Accelerated Exlansion

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Discussion Overview

The discussion revolves around cosmological theories that can explain the accelerated expansion of the universe, with a focus on Brans-Dicke theory and alternative models. Participants explore various theoretical frameworks, including the concordance model and other approaches, while addressing the challenges in predicting certain constants within these theories.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant introduces Brans-Dicke theory as a framework for understanding accelerated expansion and seeks alternative cosmological theories.
  • Another participant identifies the \LambdaCDM model as the concordance model, noting its prevalence in cosmology textbooks and its ability to describe the expansion history.
  • A participant mentions that Einstein's general relativity includes a cosmological constant that accounts for the observed accelerated expansion, but highlights the challenge of predicting its value within the theory.
  • Loop quantum cosmology (LQC) is suggested as another strong model, although the participant admits limited knowledge on this topic compared to \LambdaCDM.
  • Several participants provide links to free textbooks and resources related to cosmological models and general relativity, indicating a collaborative effort to share knowledge.

Areas of Agreement / Disagreement

Participants present multiple competing views on cosmological theories, with no consensus reached regarding the best model to explain the accelerated expansion of the universe.

Contextual Notes

There are unresolved questions regarding the prediction of the cosmological constant within general relativity and the varying degrees of success among alternative theories. The discussion reflects a range of assumptions and perspectives on the topic.

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I have just seen this paper on constructing a cosmology for the accelerated expansion of the universe through BransDicke theory

http://arxiv.org/pdf/1402.4291v1.pdfBesides this approach

What are the alternative or leading cosmological theories that can predict to some fairly strong confidence the accelerating expansion of the universe
 
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The concordance model is [itex]\Lambda[/itex]CDM. Though its certainly not the only model that can show the expansion history. The FLRW metrics of the Lambda CDM can easily do that.. its also the model most used in most of the cosmology textbooks
 
Einstein's general relativity has a cosmological constant term in it which produces, as far as I know, exactly the accelerated expansion we observe. So, that's one alternative, and perhaps the simplest alternative.

Now if you are asking what theories will give you this value for the cosmological constant (since it's a constant of integration in Einstein's GR, there's no way internally to the theory of predicting this constant), then there are myriad attempted possibilities with varying degrees of success (none are very close to being successful as far as I know). The accelerated expansion of the universe is, at this point, a mystery.
 
Forgot to mention another strong model is loop quantum cosmology LQC. If your interested in fields in general to describe many of the aspects of cosmology I recommend this free textbook.

"Fields"

http://arxiv.org/abs/hepth/9912205

a free textbook for LCDM can be found here

ASTROPHYSICS AND COSMOLOGY
http://arxiv.org/pdf/hep-ph/0004188v1.pdf

can't help on LQC as I study LCDM

for the various metrics of GR and SR I recommend
"Lecture Notes on General Relativity" by Matthias Blau

http://www.blau.itp.unibe.ch/newlecturesGR.pdf

I'm still studying the last article myself
 
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