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Observations are converging…

This conference explores various cosmological models such as the cosmological constant, dark energy, scalar-tensor models, and modified gravity, and discusses their implications for our understanding of the universe.

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Observations are converging…

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  1. ISAPP 2011 Observations are converging… …to an unexpected universe

  2. ISAPP 2011 Classifying the unknown, 1 • Cosmological constant • Dark energy w=const • Dark energy w=w(z) • quintessence • scalar-tensor models • coupled quintessence • mass varying neutrinos • k-essence • Chaplygin gas • Cardassian • quartessence • quiessence • phantoms • f(R) • Gauss-Bonnet • anisotropic dark energy • brane dark energy • backreaction • void models • degravitation • TeVeS • oops....did I forget your model?

  3. ISAPP 2011 Classifying the unknown, 3 • Standard cosmology: • GR gravitational equations + symmetries a) change the equations i.e. add new matter field (DE) or modify gravity (MG) b) change the symmetries i.e. inhomogeneous non-linear effects, void models, etc

  4. ISAPP 2011 Simplest MG (I): DGP (Dvali, Gabadadze, Porrati 2000) L = crossover scale: • 5D gravity dominates at low energy/late times/large scales • 4D gravity recovered at high energy/early times/small scales 5D Minkowski bulk: infinite volume extra dimension brane gravity leakage

  5. ISAPP 2011 Simplest MG (II): f(R) The simplest MG in 4D: f(R) eg higher order corrections • f(R) models are simple and self-contained (no need of potentials) • easy to produce acceleration (first inflationary model) • high-energy corrections to gravity likely to introduce higher-order terms • particular case of scalar-tensor and extra-dimensional theory

  6. ISAPP 2011 Faces of the same physics Faces of the same physics Extra-dim. degrees of freedom Higher order gravity Coupled scalar field Scalar-tensor gravity

  7. ISAPP 2011 Is this already ruled out by local gravity? is a scalar-tensor theory with Brans-Dicke parameter ω=0 or a coupled dark energy model with coupling β=1/2 β λ Adelberger et al. 2005

  8. ISAPP 2011 The fourfold way out of local constraints { depend on time depend on space depend on local density depend on species

  9. ISAPP 2011 The simplest case Turner, Carroll, Capozziello etc. 2003 In Einstein Frame …a particular case of coupled dark energy

  10. ISAPP 2011 R-1/R model :the φMDE today mat rad field rad mat field MDE In Jordan frame: Caution: Plots in the Einstein frame! instead of !!

  11. ISAPP 2011 Sound horizon in R+R - n model in the Matter Era ! L.A., D. Polarski, S. Tsujikawa, PRL 98, 131302, astro-ph/0603173

  12. ISAPP 2011 A recipe to modify gravity Can we find f(R) models that work?

  13. ISAPP 2011 c LGC+Cosmology Take for instance the ΛCDM clone Applying the criteria of LGC and background cosmology i.e. ΛCDM to an incredible precision

  14. Space-time geometry The most general (linear, scalar) metric at first-order background Full metric reconstruction at first order requires 3 functions perturbations ISAPP 2011

  15. Two free functions At linear order we can write: • Poisson equation • zero anisotropic stress ISAPP 2011

  16. Two free functions At linear order we can write: • modified Poisson equation • non-zero anisotropic stress ISAPP 2011

  17. Modified Gravity at the linear level • standard gravity Boisseau et al. 2000 Acquaviva et al. 2004 Schimd et al. 2004 L.A., Kunz &Sapone 2007 • scalar-tensor models • f(R) Bean et al. 2006 Hu et al. 2006 Tsujikawa 2007 • DGP Lue et al. 2004; Koyama et al. 2006 • coupled Gauss-Bonnet see L. A., C. Charmousis, S. Davis 2006 ISAPP 2011

  18. Reconstruction of the metric massive particles respond to Ψ massless particles respond to Φ-Ψ ISAPP 2011

  19. Reality check Density fluctuation in space θ Matter power spectrum Galaxy power spectrum Galaxy power spectrum in redshift space ISAPP 2011

  20. Peculiar velocities r = v/H0 . ISAPP 2011

  21. Peculiar velocities redshift distortion parameter Kaiser 1987 ISAPP 2011

  22. Weak lensing Background sources Dark matter halos Observer Radial distances depend on geometry of Universe Foreground mass distribution depends on growth/distribution of structure ISAPP 2011

  23. The Euclid theorem 4 unknown functions: Observables: Conservation equations: We can measure 3 combinations and we have 1 theoretical relation… Theorem: lensing+galaxy clustering allows to measure all (total matter) perturbation variables at first order without assuming any specific gravity theory ISAPP 2011

  24. The Euclid theorem From these we can derive the deviations from Einstein’s gravity: ISAPP 2011

  25. Euclid Surveys Euclid in a nutshell • Simultaneous (i) visible imaging (ii) NIR photometry (iii) NIR spectroscopy • 20,000 square degrees • 100 million redshifts, 2 billion images • Median redshift z = 1 • PSF FWHM ~0.18’’ • Final ESA selection (launch 2017) • 500 peoples, 10 countries Euclid satellite

  26. Bertinoro 2011 Real-time cosmology

  27. ISAPP 2011 One null cone time comoving dist.

  28. ISAPP 2011 One null cone One null cone time com. dist. VOID

  29. ISAPP 2011 Cosmic Degeneracy 3 Tomita 2001 Celerier 2001 Alnes & Amarzguioi 2006,07 Bassett et al. 07 Clifton et al. 08 Notari et al. 2005-08 Marra et al. 08 Garcia-Bellido & Haugbolle 2008 Garcia-Bellido & Haugbolle 2008 void model

  30. ISAPP 2011 Two null cones are better than one! time com. dist. VOID Mashhoon & Partovi 1985 Uzan, Clarkson & Ellis 2007 Quartin, Quercellini, L.A. 2009

  31. ISAPP 2011 Sandage 1962

  32. ISAPP 2011 Loeb 1998

  33. ISAPP 2011 The Sandage effect Corasaniti, Huterer, Melchiorri 2007 Balbi & Quercellini 2007

  34. ISAPP 2011 EELT

  35. ISAPP 2011 CODEX at EELT 2010 today... ...ten years later

  36. ISAPP 2011 CODEX at EELT • large colleting area • high resolution spetrographs • stable, low-peculiar motion targets: Lyman-alpha lines Liske et al. 2008

  37. ISAPP 2011 Two null cones are better than one! Two null cones are better than one! time com. dist. 5yrs 10yrs VOID 15yrs M. Quartin & L. A. 2009

  38. ISAPP 2011 Evolution Rest of the Universe Rest of the Universe Us Us Ptolemaic system, I century LTB void model, XXI century

  39. ISAPP 2011 Cosmic Parallax astrometric satellites GAIA, SIM, Jasmine etc: 1-100 µas Quercellini, Quartin & LA, Phys. Rev. Lett. 2009 arXiv 0809.3675 LTB void model

  40. ISAPP 2011 Lemaitre-Tolman-Bondi models Exact solution in matter-dominated universe: Garcia-Bellido & Haugbolle 2008

  41. ISAPP 2011 Garcia-Bellido & Haugbolle 2008 Quercellini, Quartin & LA, arXiv 0809.3675

  42. ISAPP 2011 Gaia: Complete, Faint, Accurate

  43. ISAPP 2011 Cosmic Parallax Quercellini, Quartin & LA, arXiv 0809.3675

  44. ISAPP 2011 Garcia-Bellido & Haugbolle 2008 Quercellini, Quartin & LA, arXiv 0809.3675

  45. ISAPP 2011 Garcia-Bellido & Haugbolle 2008 Quercellini, Quartin & LA, arXiv 0809.3675

  46. ISAPP 2011 Not only LTB a(t) Bianchi I b(t) c(t)

  47. ISAPP 2011 Current limits on anisotropy at z = 1000 at z = 0 in a ΛCDM universe at z = 0 in anisotropic dark energy

  48. ISAPP 2011 Anisotropic dark energy Mota & Koivisto 2008, Barrow, Saha, Bruni, Rodrigues and many others.. C. Quercellini, P. Cabella, L.A., M. Quartin, A. Balbi 2009

  49. ISAPP 2011 • Future of Dark Energy research • Move from background to perturbations • Test for gravity/new physics at large scales • New full sky surveys at redshift beyond unity • Find new observables: eg real-time cosmology

  50. Peculiar Acceleration The PA is a direct probe of the gravitational potential: it does not assume virialization or hydrostatic equilibrium. ISAPP 2011

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