Which cosmological model do you find most compelling?

AI Thread Summary
The discussion centers on preferences for cosmological models, particularly the standard LCDM model, which is favored for fitting observations and simplicity. Participants acknowledge the uncertainty in determining the actual model that describes the universe. One contributor expresses a preference for the "de Sitter universe," highlighting its historical significance and its unique perspective on the redshift-distance relationship. This model is noted for being an approximation of a universe with minimal matter compared to vacuum. Overall, the conversation emphasizes the complexities and assumptions inherent in choosing a cosmological model.
kathykoo9
Messages
7
Reaction score
0
Which of the common cosmological models do you prefer and why?
Assume we don't know which if any of the models is the actual one that matches the universe.
 
Space news on Phys.org
The standard LCDM model of course. It fits observations the best.
 
nicksauce said:
The standard LCDM model of course. It fits observations the best.
...and also has the virtue of being the simplest that matches the observations.
 
I think you missed that sentence:
kathykoo9 said:
Assume we don't know which if any of the models is the actual one that matches the universe.


But really, I just can't imagine I knew nothing about the universe and the make my choice. For example, even the basic assumption of the common models (homogeneity) is based on observation. I'm already preconceived.
 
I would probably go for the "de Sitter universe" as he first presented it in 1917 in his famous at the time but nowadays mostly ignored or distorted three part paper: “A. Einstein’s Theory of Gravitation and its Astronomical Consequences”. In it he describes what he called "model B" universe to distinguish it from the one proposed that same year by Einstein. In this universe you can find the "de sitter effect" which predicted the redshift- distance relationship in a very different light with respect to the way it is now understood,and that Hubble used to explain in several instances his redshift-distance observations. However, it works only as an approximation to a universe like the one we observe in which there is litle matter in proportion to vacuum since "de Sitter universe" is an empty universe with no matter.
 
https://en.wikipedia.org/wiki/Recombination_(cosmology) Was a matter density right after the decoupling low enough to consider the vacuum as the actual vacuum, and not the medium through which the light propagates with the speed lower than ##({\epsilon_0\mu_0})^{-1/2}##? I'm asking this in context of the calculation of the observable universe radius, where the time integral of the inverse of the scale factor is multiplied by the constant speed of light ##c##.
The formal paper is here. The Rutgers University news has published a story about an image being closely examined at their New Brunswick campus. Here is an excerpt: Computer modeling of the gravitational lens by Keeton and Eid showed that the four visible foreground galaxies causing the gravitational bending couldn’t explain the details of the five-image pattern. Only with the addition of a large, invisible mass, in this case, a dark matter halo, could the model match the observations...
Hi, I’m pretty new to cosmology and I’m trying to get my head around the Big Bang and the potential infinite extent of the universe as a whole. There’s lots of misleading info out there but this forum and a few others have helped me and I just wanted to check I have the right idea. The Big Bang was the creation of space and time. At this instant t=0 space was infinite in size but the scale factor was zero. I’m picturing it (hopefully correctly) like an excel spreadsheet with infinite...
Back
Top