L. Perivolaropoulos Department of Physics University of Ioannina

download L. Perivolaropoulos   Department of Physics University of Ioannina

of 22

  • date post

  • Category


  • view

  • download


Embed Size (px)


Open page. Is ΛCDM the Correct Model?. L. Perivolaropoulos http://leandros.physics.uoi.gr Department of Physics University of Ioannina. Structure of Talk. Model Classes - Key Questions. Geometric Constraints: Standard Rulers - Standard Candles. - PowerPoint PPT Presentation

Transcript of L. Perivolaropoulos Department of Physics University of Ioannina

  • L. Perivolaropoulos http://leandros.physics.uoi.grDepartment of PhysicsUniversity of IoanninaOpen page

  • Model Classes - Key QuestionsGeometric Constraints: Standard Rulers - Standard CandlesComparison of Recent Standard Candle SnIa Data: -Figure of Merit -Consistency with CDM -Consistency with Standard Rulers Potential Conflicts of CDM with Data: - Large Scale Velocity Flows - Cluster Halo Profiles - Emptiness of Voids - Brightness of High z SnIaConclusionDynamical Constraints: Linear Growth of Perturbations

  • Dark EnergyAllowed SectorCosmological ConstantModified Gravity Allowed SectorForbidden (ghosts)Expansion HistoryEq. of state evolution Gmn - L gmn = k TmnGmn = k (Tmmn+ T)Gmn = k Tmmn

  • Is General Relativity the correct theory on cosmological scales? What is the most probable form of w(z) and what forms of w(z) can be excluded? What is the consistency level of CDM (GR + ) with cosmological observations? What is the recent progress?

  • Luminosity Distance (standard candles: SnIa,GRB):Angular Diameter Distance (standard rulers: CMB sound horizon, clusters):flatDirect Probes of H(z):Significantly less accurate probes S. Basilakos, LP, MBRAS ,391, 411, 2008 arXiv:0805.0875

  • Parametrize H(z):Minimize:Standard Candles (SnIa)Standard Rulers (CMB+BAO)Lazkoz, Nesseris, LP JCAP 0807:012,2008. arxiv: 0712.1232ESSENCE (+SNLS+HST) dataWMAP3+SDSS(2007) dataChevallier, Pollarski, Linder

  • Q2: What is the consistency of each dataset with CDM? Q3: What is the consistency of each dataset with Standard Rulers? J. C. Bueno Sanchez, S. Nesseris, LP, 0908.2636 Q1: What is the Figure of Merit of each dataset?

  • The Figure of Merit: Inverse area of the 2 parameter contour. A measure of the effectiveness of the dataset in constraining the given parameters.


  • ESSENCE+SNLS+HST dataSNLS 1yr dataTrajectories of Best Fit Parameter PointThe trajectories of SNLS and Constitution clearly closer to CDM for most values of 0mGold06 is the furthest from CDM for most values of 0mQ: What about the -distance (d) from CDM?0m=0.24

  • ESSENCE+SNLS+HST dataTrajectories of Best Fit Parameter PointConsistency with CDM Ranking:

  • Consistency with Standard Rulers Ranking:ESSENCE+SNLS+HSTTrajectories of Best Fit Parameter Point

  • Consistency with CDM RankingConsistency with Standard Rulers Ranking:Identical Ranking Sequence! (Independent Criteria)

  • Trajectories of Best Fit Parameter PointConsistency with Dynamical Dark Energy Ranking:

  • Consistency with CDM Ranking:Consistency with Standard Rulers Ranking:Consistency with Dynamical Dark Energy RankingIdentical Ranking SequenceReversed Ranking SequenceTests Quality of SnIa DataJ. C. Bueno Sanchez, S. Nesseris, LP, 09082636

  • Flat, CDM remains at 1 (or less) distance from the best fit with trend to further improve consistency with geometric probesThe 2 parameter contour areas have improved by a factor of about 4 since 2005 while the number of filtered SnIa has increased by about the same factor. The consistency with standard rulers remains good (except for Gold06 dataset)Q: Which Dark Energy Probes have weak consistency with CDM?

  • Large Scale Velocity Flows- Predicted: On scale larger than 50 h-1Mpc Dipole Flows of 110km/sec or less. - Observed: Dipole Flows of more than 400km/sec on scales 50 h-1Mpc or larger. - Probability of Consistency: 1%Cluster and Galaxy Halo Profiles:- Predicted: Shallow, low-concentration mass profiles - Observed: Highly concentrated, dense halos - Probability of Consistency: 3-5%Bright High z SnIa:- Predicted: Distance Modulus of High z SnIa close to best fit CDM - Observed: Dist. Modulus of High z SnIa lower (brighter) than best fit CDM - Probability of Consistency for Union and Gold06: 3-6%The Emptiness of Voids:- Predicted: Many small dark matter halos should reside in voids. - Observed: Smaller voids (10Mpc) look very empty (too few dwarf galaxies) - Probability of Consistency: 3-5%From LP, 0811.4684R. Watkins et. al. , 0809.4041Broadhurst et. al. ,ApJ 685, L5, 2008, 0805.2617, S. Basilakos, J.C. Bueno Sanchez, LP., 0908.1333, PRD, 80, 043530, 2009. LP and A. Shafielloo , PRD 79, 123502, 2009, 0811.2802P.J.E. Peebles , astro-ph/0101127, Klypin et. al. APJ, 522, 82, 1999, astro-ph/9901240

  • The dipole moment of large scale velocity flows (bulk flow) extends on scales up to 100h-1 Mpc with amplitude larger than 400km/sec.CDM predicted amplitude on scale larger than 50h-1 Mpc : 110km/secFrom R. Watkins, H. Feldman and M. J. Hudson, 0809.4041

  • NFW profile:CDM prediction:The predicted concentration parameter cvir is significantly smaller than the observed.From S. Basilakos, J.C. Bueno-Sanchez and LP, PRD, 80, 043530, 2009, 0908.1333.Data from:Navarro, Frenk, White, Ap.J., 463, 563, 1996

  • Parametrization:Measure growth function of cosmological perturbations:Evolution of (sub-Hubble scales) :James, Dutta, LP., 0903.5296Horizon scalesHorizon scales

  • Fit to LSS data:CDM provides an excellent fit to the linear perturbations growth dataS. Nesseris, LP, Phys.Rev.D77:023504,2008 best fitCDM

  • The consistency of CDM with geometric probes of accelerating expansion is very good and it appears to be further improving with time.There are a few puzzling potential conflicts of CDM specific cosmological data mainly related with dynamical large scale structure probes.Data from dynamical probes on the linear growth of perturbations are currently not as constraining as geometric probes but they also have good consistency with CDM.