School of Mathematical Sciences

Is the integrated Sachs-Wolfe effect from super-structures still a problem for LambdaCDM? menu

Is the integrated Sachs-Wolfe effect from super-structures still a problem for LambdaCDM?

Speaker: 
Shaun Hotchkiss
Date/Time: 
Wed, 22/02/2012 - 16:30
Room: 
Maths 103
Seminar series: 

In any region of the universe where the gravitational potential decays over time large-scale structure will produce a redshift in the cosmic microwave background. This is known as the integrated Sachs-Wolfe (ISW) effect. A cosmological constant causes such a decay and as such the ISW effect is an important consistency test of the standard cosmological model. The ISW imprint of very large (super) structures has reportedly been detected with >4\sigma significance. I will discuss this observation and the LambdaCDM prediction for it. It is seen that the observed signal is >3-sigma larger than expectations. No solution to this 'ISW mystery' is yet known; however I will discuss some interesting directions worth further exploration.