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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. L. Dark Energy Evidence. 4%. f. WMAP+ACBAR+CBI+2dF+Lyman . L. Cosmological Constant Problem.
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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
L Dark Energy Evidence 4% f WMAP+ACBAR+CBI+2dF+Lyman
L Cosmological Constant Problem G=8 T f
L Cosmological Constant Problem Geometry G+ g=8 T +Vg f Quantum Vacuum
L Cosmological Constant Problem : ? |-V|/M4Planck10-120 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: bispectrum L Giovi et al. 2003, in preparation f
Quintessence & Large Scale Structure L f 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
Extended Quintessence L dk2=4p k3(dr /r)k2 Gravity m c2eff, 1 f Perrotta, Baccigalupi, Matarrese 2000, Perrotta & Baccigalupi 2002
L Conclusions • Discovery • Concerning Vacuum Energy • Observable, Here and Now! • Probes: WMAPext+LSS, LSST, Planck, SNAP f
L Dark Energy f