Kinetic Sunyaev-Zel dovich effect: Dark Energy, Modified gravity, Massive Neutrinos

Transcription

1 Kinetic Sunyaev-Zel dovich effect: Dark Energy, Modified gravity, Massive Neutrinos Eva-Maria Mueller Work in collaboration with Francesco De Bernardis, Michael D. Niemack, Rachel Bean [arxiv: , arxiv: ]

2 Kinetic SZ effect CMB photon passing though clusters are Doppler shifted due to bulk motion of clusters distortion of the CMB spectrum T ksz T CMB = τ vpec c δ + ikv =0 optical depth of cluster

3 Mean pairwise statistics Problem: ksz: weak frequency dependence ksz: Signal is small Hard to observe Solution: Cross-correlate CMB maps with cluster positions and redshift to extract the ksz signal Mean pairwise velocity mean pairwise momentum ned.ipac.caltech.edu Hand et. al 2012

4 Dark Energy and Modified Gravity V (r) [km/s] z =0.15 w 0 = 1.0, γ =0.55 w 0 = 0.8, γ =0.55 w 0 = 1.2, γ =0.55 w 0 = 1.0, γ =0.66 w 0 = 1.0, γ =0.44 V (r, a) = 2 3 H(a)a f(a) r ξ halo (r, a) 1+ξ halo (r, a) Growth rate f: Sheth et. al 2001 V (r)/v (r) fid Mueller, De Bernardis, Bean, Niemack (arxiv ) r [Mpc/h] Mueller, De Bernardis, Bean, Niemack (arxiv ) f(a) =Ω m (a) γ γ GR =0.55 γ MG =0.55 Can test modified gravity and dark energy!

5 Massive neutrinos V (r) [km/s] normal hierarchy at z = 0.15 mν =0 mν = 100 mev mν = 300 mev mν = 600 mev Neutrino Oscillation experiments: Neutrinos are massive! normal : m 1 <m 2 << m 3 inverted : m 3 << m 1 m 2 V (r)/v (r) fid r [Mpc/h] Mueller, De Bernardis, Bean, Niemack (arxiv: ) degenerate : m 1 m 2 m 3 Scale dependency!

6 Non-Gaussianity V (r) [km/s] z =0.15 f NL =0 f NL = 500 f NL = 100 f NL = 100 f NL = 500 Halo bias: b(k, M, z) =b G (M,z)+ b NG (k, M, z) 50 0 Gaussian Non-Gaussian correction V (r)/v (r) fid r [Mpc/h] preliminary work b loc NG(k, M, z) f NL k 2

7 Potential of ksz surveys Stage III Stage IV +CMB FoM GR FoM MG 9 33 γ/γ DETF FoM GR FoM MG γ/γ γ Stage IV Stage III Stage II DETF Stage III Current constraints: BOSS: γ = ksz more powerful for constraining modified gravity than dark energy equation of state CMB + DETF Stage III w 0 Mueller, De Bernardis, Bean, Niemack (arxiv )

8 Potential of ksz surveys m ν Minimal ΛMDM Planck ksz+planck Planck+len ksz+planck+len Ω m h 2 General ΛMDM w 0 General ΛMDM w a conservative mν < ev Planck+Stage IV ksz Mueller, De Bernardis, Bean, Niemack (arxiv ) optimistic mν < ev Planck: mν < ev

9 Pairwise momentum Pairwise velocity T ksz T CMB = τ vpec c τ How well do we know the optical depth of clusters? Fitting function from Hydro simulations Combine thermal SZ and X-ray observations Polarization signal from scattering Use scatter in forecasts τ from hydro-sims* as a proxy for the uncertainty in *Private communication with N. Battaglia

10 Stage IV Stage III Stage II ksz+cmb priors Introduce nuisance parameter: Marginalize over the amplitude, i.e. optical depth γ/γ b τ (z) b τ ˆV (z) =b τ (z)v (z) add prior on the τ -bias b prior τ Need information on the optical depth Mueller, De Bernardis, Bean, Niemack (arxiv ) But: Massive neutrino and inflation constraints are robust to uncertainty in the amplitude due to scale dependency!

11 Concluding thoughts: Extract ksz signal: Cross-correlating CMB and LSS Mean pairwise velocity of clusters ksz surveys have the potential to constrain: Dark Energy and Modified Gravity Massive Neutrinos Inflation Major uncertainty is the optical depth of clusters

12 Thank you!