CMB but also Dark Energy Carlo Baccigalupi, Francesca Perrotta
Work Fun Theory, Extended Quintessence, funny effects of Gravity and Dark Energy Coupling Phenomenology, CMB spectrum and bispectrum, B modes, acceleration and structure formation
“Quintessence’’ models of DE A classical, minimally-coupled scalar field evolves in a potential V while its energy density and pressure combine to produce a negative equation of state w=p/ Fine-tuning problem: in analogy with the need to tune initial values of to get the observed energy density and equation of state; “Coincidence’’ problem: why m ~ just today ? Search for ATTRACTOR SOLUTIONS (“tracking fields”)
Perrotta F., Matarrese S., Baccigalupi C., Phys. Rev. D 61 (2000) Extended Quintessence
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 at early times. EQ admits tracking trajectories AND they are good trackers (large basin of attraction)
rr mm (mc) R-boost (mc) (TEQ) (TEQ)
Approaching without fine-tuning Matarrese S., Baccigalupi C., Perrotta F., to appear on Phys. Rev. D W 0 = , TEQ for different initial K,V
W 0 = for minimally coupled Q and different initial values of
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 Acquaviva V., Baccigalupi C., Perrotta F., 2004
Dark Energy and CMB
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=w 0 +(1-a)(w 1 -w 0 ) Used for ~ 10 papers
ISW and Projection
CMB C l s and Dark Energy ISW killed by Cosmic Variance Projection degenerated with s, H 0, 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
CMB C l s and Dark Energy Phys.Rev.D65, , 2002
CMB C l s and Dark Energy Phys.Rev.D65, , 2002 Efstathiou Tensor Degeneracy, 2003
B l m l` m` l`` m`` =a lm a l`m` a l``m`` a lm = s ( )Y lm ( )d B l l`l`` = m m` m`` ( m l m` l` m`` l`` ) a lm a l`m` a l``m`` l l` l`` ( ) ´ T( )/T Beyond C l s: CMB bispectrum
=0 =0 0 0 Weak lensing and CMB bispectrum
CMB bispectrum and w 1 w 1 =-0.3 w 0 =w 1 =-0.9
Beyond C l s: B modes in CMB Polarisation
Dark Energy and Structure Formation
DE, lin. Pert., Carlo Baccigalupi DE theory & models, Francesca Perrotta Trieste
DE, lin. Pert., Carlo Baccigalupi DE theory & models, Francesca Perrotta Lensing, Str.Form., Matthias Bartelmann Lensing, Massimo Meneghetti Heidelberg
DE, lin. Pert., Carlo Baccigalupi DE theory & models, Francesca Perrotta Lensing, Str.Form., Matthias Bartelmann Lensing, Massimo Meneghetti Str. Form., Lauro Moscardini N-body, Klaus Dolag Str. Form., Giuseppe TormenBologna Padua Garching
Cluster Concentration Astron.Astrophys. 416, 853, 2004
Simulating Arcs astro-ph/
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)