Mission to Probe the Universe's Darkest Secrets

[skydivephil]

http://phys.org/news/2012-06-mission-go-ahead-probe-universe-darkest.html

So what reasonable expectation can we have from this mission?

 

[Chalnoth]

http://phys.org/news/2012-06-mission-go-ahead-probe-universe-darkest.html

So what reasonable expectation can we have from this mission?

We should be able to have far, far better constraints on the nature of the accelerated expansion. This kind of satellite can really do a great job at nailing that down. The website there mentions dark matter, but that's basically a solved problem, at least in terms of its effects on cosmology.

I'd say that there's about an 80%-90% chance that Euclid will confirm the Lambda-CDM model of cosmology yet again. So a fairly small chance that it will detect something fundamentally new about the nature of the accelerated expansion. It will, however, bring in a treasure trove of information for people interested in studying galaxies, as it will be observing very large numbers of galaxies in the process of doing its mission to measure the accelerated expansion.

 

[skydivephil]

Are we talking about trying to measure w to a higher level of accuracy? If so the only revolutionary discovery will be if we got a non -1 answer right?

 

[Chalnoth]

Are we talking about trying to measure w to a higher level of accuracy? If so the only revolutionary discovery will be if we got a non -1 answer right?

Well, there are other ways to parameterize dark energy, but yes, this is essentially correct.

 

[nicksauce]

Are we talking about trying to measure w to a higher level of accuracy? If so the only revolutionary discovery will be if we got a non -1 answer right?

I think they should also be able to measure/constrain the first time derivative of w as well?

 

[Chalnoth]

I think they should also be able to measure/constrain the first time derivative of w as well?

Well, what's usually done now is to take w_0 (the value of w today) and w_a (the derivative of w with respect to the scale factor a). But there are other possibilities as well. Either way, Euclid should offer some pretty tremendous constraints on dark energy compared to current constraints, no matter what sort of parameters you use.