Dark Energy L The first Surprise in the era of precision cosmology? f
L Dark Energy Evidence f
L Dark Energy Evidence f Percival et al. MNRAS 327 1297 2001
WMAP+ACBAR+CBI+2dF+Lyman Dark Energy Evidence 4% f WMAP+ACBAR+CBI+2dF+Lyman
Cosmological Constant Problem G=8 T f
Cosmological Constant Problem Geometry G+ g=8 T +Vg f Quantum Vacuum
Cosmological Constant Problem : ? |-V|/M4Planck 10-120 f 4 V: ? M Planck
?? L for Physics Two ? Why so small with respect to any particle physics scale ? Why comparable to the cosmological matter density today f
L Dark Energy Models Trans Planckian: energy stored in perturbation modes on super-horizon scales (Mersini et al., PRD64 043508, 2001) Spacetime microstructure: self-adjusting spacetime capable to absorbe vacuum energy (Padmanabhan, gr-qc/0204020) Matter-Energy Transition: dark matter converts to dark energy at low redshifts (astro-ph/0203383) Brane worlds: brane tension (Shani & Sthanov astro-ph/0202346); cyclic-ekpyrotic cosmic vacuum (Steinhardt &Tutok hep-th/0111098) Quintessence: tracking scalar fields (Steinhardt, Wang & Zlatev, PRD59, 123504, 1999; Ratra & Peebles, Wetterich 1988) Extended Quintessence: non-minimal coupling to Gravity (Uzan Chiba, Perrotta, Baccigalupi, Matarrese, PRD61, 023507, 2000 Coupled Quintessence: coupling with dark matter (Amendola, Pietroni...) f
L Quintessence Field (t)+(t,x), U() f
L Effects on the CMB Projection Integrated Sachs-Wolfe f
Quintessence & CMB: wf ,Wf L f Baccigalupi et al. 2002
Quintessence & CMB: wf ,Wf L f
Quintessence & CMB: bispectrum Giovi et al. 2003, in preparation f
L f Quintessence & Large Scale Structure Growth Factor, Transfer Function: Ma et al. 1998 Aperture Mass Statistics: Bartelmann, Perrotta, Baccigalupi 2002 Halo Concentration: Bartelmann et al. A&A 2002 N-body: Maccio’ et al. 2003
L f Extended Quintessence Gravity m c2eff, 1 dk2=4p k3(dr /r)k2 Gravity m c2eff, 1 f Perrotta, Baccigalupi, Matarrese 2000, Perrotta & Baccigalupi 2002
L f Conclusions Discovery Concerning Vacuum Energy Observable, Here and Now! Probes: WMAPext+LSS, LSST, Planck, SNAP f
L Dark Energy f