CMB but also Dark Energy

1. CMB but also Dark Energy Carlo Baccigalupi, Francesca Perrotta

2. Work Fun • Theory, Extended Quintessence, funny effects of Gravity and Dark Energy Coupling • Phenomenology, CMB spectrum and bispectrum, B modes, acceleration and structure formation

3. “Quintessence’’ models of DE A classical, minimally-coupled scalar field evolves in a potential V(f), while its energy density and pressure combine to produce a negative equation of state w=p/r • Fine-tuning problem: in analogy with L, the need to tune initial values of f to get the observed energy density and equation of state; • “Coincidence’’ problem: why rm ~ rfjust today ?  Search for ATTRACTOR SOLUTIONS (“tracking fields”)

4. Extended Quintessence Perrotta F., Matarrese S., Baccigalupi C., Phys. Rev. D 61 (2000) 023507

5. R-boost Klein-Gordon equation in EQ: • Since R diverges as a-3 as a 0 (if non-relativistic species are • present) , an “effective” potential is generated in the KG equation, • boosting the dynamics of f at early times. • EQ admits tracking trajectories AND they are good trackers (large basin of attraction)

6. rr rm R-boost rf(TEQ) r*f(TEQ) r*f(mc) rf(mc)

7. Approaching L without fine-tuning Matarrese S., Baccigalupi C., Perrotta F., to appear on Phys. Rev. D W0= -0.999, TEQ for different initial K,V

8. W0= -0.999 for minimally coupled Q and different initial values of f

9. Linear and non-linear perturbations • Clustering properties: scalar field perturbations may interact with matter perturbations in EQ models. • Weak lensing : variations of G induce corrections in distance calculations; perturbations gain a new d.o.f., the anisotropic stress • CMB effects (ISW, projection, lensing, bispectrum) • Effects on LSS and structure formation • Backreaction of EQ perturbations on the background metric? (difference between Einstein tensor formed from the averaged metric and the averaged value of the Einstein tensor) • Search for purely gravitational explanation of cosmic acceleration (EQ without potential) Perrotta F., Baccigalupi 2002; Perrotta et al. 2003 Acquaviva V., Baccigalupi C., Perrotta F., 2004

10. Dark Energy and CMB

11. DEfast • A cmbfast 4.0 based code for dark energy cosmologies • Scalar field dark energy models in ordinary or scalar-tensor cosmologies • Effective dark energy models (Linder 2003): w=w0+(1-a)(w1-w0) • Used for ~ 10 papers

12. ISW and Projection

13. CMB Cls and Dark Energy • ISW killed by Cosmic Variance • Projection degenerated with Ws, H0, K, … but still the basic effect on which CMB constraints on dark energy are based so far • Projection unable to probe w(z), two redshift integrals wash that out

14. CMB Cls and Dark Energy Phys.Rev.D65, 063520, 2002

15. CMB Cls and Dark Energy Efstathiou Tensor Degeneracy, 2003 Phys.Rev.D65, 063520, 2002

16. Beyond Cls: CMB bispectrum Q (W ) ´dT(W )/T alm=sQ (W )Ylm(W )dW Blm l`m`l``m``=alm al`m` al``m`` Bl l`l``=åm m` m`` (mlm`l`m``l``) alm al`m` al``m`` l l`` l`

17. Weak lensing and CMB bispectrum < Blm l`m`l``m`` >=0 < Blm l`m`l``m`` >0

18. CMB bispectrum and w1 w1=-0.3 w0=w1=-0.9

19. Beyond Cls: B modes in CMB Polarisation

22. Dark Energy and Structure Formation

23. DE theory & models, Francesca Perrotta DE, lin. Pert., Carlo Baccigalupi Trieste

24. Lensing, Str.Form., Matthias Bartelmann Lensing, Massimo Meneghetti Heidelberg DE theory & models, Francesca Perrotta DE, lin. Pert., Carlo Baccigalupi

25. Lensing, Str.Form., Matthias Bartelmann Lensing, Massimo Meneghetti Garching DE theory & models, Francesca Perrotta N-body, Klaus Dolag DE, lin. Pert., Carlo Baccigalupi Padua Str. Form., Giuseppe Tormen Bologna Str. Form., Lauro Moscardini

26. Cluster Concentration Astron.Astrophys. 416, 853, 2004

27. Simulating Arcs astro-ph/0405070

28. More… • CMB bispectrum, how much does it helps? • Weak lensing and B modes on large scales in dark energy cosmologies • Non-linear structures and CMB lensing… • Bring the news on CMB and SNIa together, a Beyond Einstein proposal in preparation (Linder & Baccigalupi)