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L. Perivolaropoulos http://leandros.physics.uoi.gr Department of Physics University of Ioannina Open page S. Nesseris, LP, astro-ph/0610092, astro-ph/0611238

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Observational Probes of the Accelerating Expansion w(z) is close to -1 w(z) crossing the w=-1 w(z) crossing the w=-1 Inconsistent with Minimally Coupled Quintessence and also with Scalar Tensor Quintessence if G(t) is increasing with time. Marginal Consistency of Scalar-Tensor Quintessence with Observed Accelerating Expansion Maximal Agreement of Scalar-Tensor Quintessence with the Full Parameter Range of Observed Acelerating Expansion G(t) can not increase rapidly with t (not sharp Maximum) Close to Extremum (Solar System) G(t) decreases with t (close to a Minimum) Close to Extremum (Solar System) SNLS

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All best fit parameterizations cross the phantom divide at z~0.25 The parametrization with the best χ 2 is oscillating Lazkoz, Nesseris, LP 2005

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Trunc. Gold (140 points, z<1) Full Gold (157 points, z<1.7)SNLS (115 points z<1) SNLS data show no trend for crossing the phantom divide w=-1! S. Nesseris, L.P. Phys. Rev. D72:123519, 2005 astro-ph/0511040

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Gold dataset Riess -et. al. (2004) SNLS dataset Astier -et. al. (2005) Other data: CMB, BAO, LSS, Clusters S. Nesseris, L.P. astro-ph/0610092 Other data: CMB, BAO, LSS, Clusters Gold dataset Riess -et. al. (2004) SNLS dataset Astier -et. al. (2005) Other data: CMB, BAO, LSS, Clusters Minimize: Eisenstein et. al. 2005 Wang, Mukherjee 2006 Allen et. al. 2004 2dF:Verde et. al. MNRAS 2002

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Riess et. al. astro-ph/0611572

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Old Gold Filtered Gold+New HST Filtered Gold+New HST+Best of SNLS S. Nesseris, LP in prep.

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Old Gold Filtered Gold+New HST Filtered Gold+New HST+Best of SNLS

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Q1: What theories are consistent with range of observed H(z)? Cosmological Constant Quintessence Extended (Scalar–Tensor) Quintessence Braneworld models (eg DGP) Barotropic fluids (eg Chaplygin Gas) Q2: What forms of H(z) are inconsistent with each theory? (forbidden sectors) Q3: What is the overlap of the observationally allowed range of H(z) with the forbidden sector of each theory? Goal: Address Q2-Q3 for Extended Quintessence

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Plausibility Arguments + Numerical Simulations Caldwel, Linder 2005 V(Φ) Φ Φ Thawing Thaw Accelerate Freezing Decelerate Freeze

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Consistency Requirements:

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Express F i in terms of G(t) current time derivatives: Ignored : (Solar System Tests, Pitjeva 2005) Gannouji, Polarski, Ranquet, Starobinsky astro-ph/0606287

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Freezing Thawing

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Freezing Thawing

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Lower bound on g 2 : Chevallier-Polarski-Linder

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Lower bound on g 2 : Upcoming Solar System Constraints on g 2 : J. Mueller 2006 Chevallier-Polarski-Linder

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SnIa Absolute Luminosity: Steps of Analysis: 1. Assume G(z) parametrization consistent with Solar System + Nucleosynthesis bounds 2. Consider modified magnitude-redshift relation 3. Minimize χ 2

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The shift of the contours is not significant compared to the area of the contours.

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Observational Probes of the Accelerating Expansion w(z) is close to -1 w(z) crossing the w=-1 w(z) crossing the w=-1 Inconsistent with Minimally Coupled Quintessence and also with Scalar Tensor Quintessence if G(t) is increasing with time. Consistency of Scalar-Tensor Quintessence Observed Accelerating Expansion Maximal Agreement of Scalar-Tensor Quintessence with the full range of observed Acelerating Expansion G(t) can not increase rapidly with t (not sharp Maximum) Close to Extremum (Solar System) G(t) decreases with t (close to a Minimum) Close to Extremum (Solar System)

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