1. Yi Mao, MIT Collaborators: Max Tegmark, Alan Guth, Matias Zaldarriaga, Matt McQuinn, Oliver Zahn, Tom Faulkner, Ted Bunn, Serkan Cabi Constraining cosmological and gravitational parameters with upcoming astrophysical data

2. Yi Mao Fermilab seminar January 23, 2008 Outline Overview: cosmological probes 21cm-tomography Overview: testing gravity Testing f(R) gravity Testing torsion gravity Outlook

3. What do we learn in cosmology? Yi Mao Fermilab seminar January 23, 2008

4. 0th order: Expansion a(t) k H(z) Yi Mao Fermilab seminar January 23, 2008

5. Distant light is { dimmed redshifted distance Vs. zH(z)

6. 1st order: Clustering C l, P(k), … Yi Mao Fermilab seminar January 23, 2008

7. CMB Z ~ 1089 Galaxy surveys z  1 Supernovae Ia Gravitational Lensing Ly-a forest

8. But the best is yet to come Precision CMB (polarization, small scales), precision lensing …… and 21cm tomography Yi Mao Fermilab seminar January 23, 2008

9. CMB Z ~ 1089 Galaxy surveys z  1 Supernovae Ia Gravitational Lensing Ly-a forest 21cm tomography

10. Yi Mao Fermilab seminar January 23, 2008 Murchison Widefield Array (MWA) Located in western Australia 500 antennas; array diameters 1500m; Measures z=6~12 Murchison Widefield Array (MWA) Located in western Australia 500 antennas; array diameters 1500m; Measures z=6~12

11. Yi Mao Fermilab seminar January 23, 2008 Other arrays Square Kilometre Array (SKA) Low Frequency Array (LOFAR) 21cm Array (21CMA) Square Kilometre Array (SKA) Low Frequency Array (LOFAR) 21cm Array (21CMA)

12. 21cm line from the Epoch of Reionization Yi Mao Fermilab seminar January 23, 2008

14. Yi Mao Fermilab seminar January 23, 2008 21cm Power spectrum 21cm power spectrum is not isotropic because of redshift space distortion!

15. How accurately can 21cm tomography constrain cosmological parameters? Yi Mao Fermilab seminar January 23, 2008

16. Yi Mao Fermilab seminar January 23, 2008

17. Yi Mao Fermilab seminar January 23, 2008 YM, Tegmark, McQuinn, Zaldarriaga & Zahn (2008) K

18. Yi Mao Fermilab seminar January 23, 2008 YM, Tegmark, McQuinn, Zaldarriaga & Zahn (2008) K

19. Ionization power spectrum modeling Yi Mao Fermilab seminar January 23, 2008

20. Yi Mao Fermilab seminar January 23, 2008 OPT

21. Yi Mao Fermilab seminar January 23, 2008 PESS

22. Yi Mao Fermilab seminar January 23, 2008 YM, Tegmark, McQuinn, Zaldarriaga & Zahn (2008) MID

23. Yi Mao Fermilab seminar January 23, 2008 YM, Tegmark, McQuinn, Zaldarriaga & Zahn (2008) K

24. Optimal array configuration Yi Mao Fermilab seminar January 23, 2008

25. Yi Mao Fermilab seminar January 23, 2008 LOFARMWASKA MID OPT Size of compact core Size of total inner core YM, Tegmark, McQuinn, Zaldarriaga & Zahn (2008)

26. Size of compact core Size of total inner core MWA in OPT model YM, Tegmark, McQuinn, Zaldarriaga & Zahn (2008) Yi Mao Fermilab seminar January 23, 2008

27. Future: 3D neutral hydrogen maps? Yi Mao Fermilab seminar January 23, 2008

28. Testing gravity in a general framework Yi Mao Fermilab seminar January 23, 2008

29. Generalize PPN A general geometry is determined by metric (g) and connection (  ), both independent of each other. Three quantities characterize the departure from Minkowski spacetime: Yi Mao Fermilab seminar January 23, 2008

30. Generalized geometry family tree

31. Constraining torsion Yi Mao Fermilab seminar January 23, 2008

32. Parametrization of torsion around Earth to linear order in  m and  a

33. Constraining torsion with GPB Image from http://einstein.stanford.edu

34. Constraining torsion with GPB YM, Tegmark, Guth, Cabi (2006)

35. Constraining f(R) gravity Yi Mao Fermilab seminar January 23, 2008

36. Yi Mao Fermilab seminar January 23, 2008 Solar system constraints on f(R) Chameleon Faulkner, Tegmark, Bunn and YM (2007)

37. Yi Mao Fermilab seminar January 23, 2008 Constraints on cubic f(R) model Faulkner, Tegmark, Bunn and YM (2007)

38. Yi Mao Fermilab seminar January 23, 2008 Outlook 3D HI mapping: direct view into the dark ages, precision constraints on cosmological parameters Better understanding of the Epoch of Reionization New tests of Einstein gravity on scales from the solar system to the cosmos Common question for cosmology and gravitation: Dark energy = cosmological constant or modified gravity? Dark matter = new particles or TeVeS/MOND? Can GR (and standard cosmological model) be further tested?

40. Tegmark & Zaldarridaga, astro-ph/0207047+updates Yi Mao Fermilab seminar January 23, 2008

41. Yi Mao Fermilab seminar January 23, 2008 21cm line Spin temperature, where Emission if Ts > Tcmb; absorption if Ts < Tcmb Saturated when Ts >> Tcmb; arbitrarily large when Ts << Tcmb The last factor makes the anisotropy! Spin temperature, where Emission if Ts > Tcmb; absorption if Ts < Tcmb Saturated when Ts >> Tcmb; arbitrarily large when Ts << Tcmb The last factor makes the anisotropy!

42. Yi Mao Fermilab seminar January 23, 2008 T s couplings Absorption of CMB photons and stimulated emission Collisions with H, e, p: Ts  T k Scattering of UV photons( the Wouthuysen-Field Effect): Ts  T Lya Absorption of CMB photons and stimulated emission Collisions with H, e, p: Ts  T k Scattering of UV photons( the Wouthuysen-Field Effect): Ts  T Lya Furlanetto, Oh & Briggs 2006

43. Yi Mao Fermilab seminar January 23, 2008 z dec ~150: compton heating. T k = T cmb before z dec ; T k ~(1+z) 2 after. Z 1 : T s = T k before z 1 ; T s  T cmb after. Z h : IGM T k > T cmb. Z c : Wouthuysen-Field Effect couples T s = T k again. Z r : reionization. z dec ~150: compton heating. T k = T cmb before z dec ; T k ~(1+z) 2 after. Z 1 : T s = T k before z 1 ; T s  T cmb after. Z h : IGM T k > T cmb. Z c : Wouthuysen-Field Effect couples T s = T k again. Z r : reionization. Thermal histroy of IGM