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Determining the expansion history of the universe with the 3D cosmic shear : 

Determining the expansion history of the universe with the 3D cosmic shear Ram Brustein, Daniel Levy Ben Gurion University astro-ph/0609543 astro-ph/0607435,

Aim : 

Aim Model independent knowledge of wtot Functional dependence of probes on the equation of state Sensitivity of probes to changes in w

Background motivation: 

Background motivation Kinematical probes Dynamical probes Depend on wtot HOW?!

Background motivation: 

Background motivation Kinematical probes Dynamical probes Depend on wtot HOW?!

Slide5: 

P. Antilogus J. Frieman et al Weller andamp; Albrecht Similar conclusions : many more I. Maor et al CANN O T MEASURE w’

Background motivation: 

Background motivation Kinematical probes Dynamical probes ? Depend on wtot HOW?!

Evolution of Ф(z): 

Evolution of Ф(z)

Solving for Φ: 

Solving for Φ EOM (for adiabatic perturbation) for a two fluid system: Φ= Φm+ ΦDE 0

Solving for Φ: 

Solving for Φ EOM (for adiabatic perturbation) for a two fluid system: Φ= Φm+ ΦDE In matter domination ΦDE decays faster than Φm 0

Solving for Φ: 

Solving for Φ The solution for cold matter in DE background wDE , Ωm

Relating shear and potential: 

Relating shear and potential

Relating shear and potential: 

Relating shear and potential

Subtracting the nonlinear part and Observables: 

Subtracting the nonlinear part and Observables

Analysis of the functional dependence: 

Analysis of the functional dependence

Parameterization after all…: 

Parameterization after all…

Influence of non-flat spectrum: 

Influence of non-flat spectrum

Measuring n ? …: 

Measuring n ? …

Summery: 

Summery wtot(z) can be measured by cosmic shear with less degeneracy or prior assumptions There’s an accuracy 'barrier' for gaining more information ~5% Few probes are needed ( dL to more then 1%...) Measuring the spectral index?... Better quantities can be found… Better calculations should be done…