Abstract
Several kinds of astronomical observations, interpreted in the framework of the standard Friedmann–Robertson–Walker cosmology, have indicated that our universe is dominated by a Cosmological Constant. The dimming of distant Type Ia supernovae suggests that the expansion rate is accelerating, as if driven by vacuum energy, and this has been indirectly substantiated through studies of angular anisotropies in the cosmic microwave background (CMB) and of spatial correlations in the large-scale structure (LSS) of galaxies. However there is no compelling direct evidence yet for (the dynamical effects of) dark energy. The precision CMB data can be equally well fitted without dark energy if the spectrum of primordial density fluctuations is not quite scale-free and if the Hubble constant is lower globally than its locally measured value. The LSS data can also be satisfactorily fitted if there is a small component of hot dark matter, as would be provided by neutrinos of mass ∼0.5 eV. Although such an Einstein–de Sitter model cannot explain the SNe Ia Hubble diagram or the position of the “baryon acoustic oscillation” peak in the autocorrelation function of galaxies, it may be possible to do so, e.g. in an inhomogeneous Lemaitre–Tolman–Bondi cosmology where we are located in a void which is expanding faster than the average. Such alternatives may seem contrived but this must be weighed against our lack of any fundamental understanding of the inferred tiny energy scale of the dark energy. It may well be an artifact of an oversimplified cosmological model, rather than having physical reality.
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References
Adams J.A., Ross G.G. and Sarkar S. (1997). Multiple inflation. Nucl. Phys. B 503: 405
Aguirre A.N. (1999). Dust versus cosmic acceleration. Astrophys. J. 512: L19
Allen S.W., Schmidt R.W., Ebeling H., Fabian A.C. and van Speybroeck L. (2004). Constraints on dark energy from Chandra observations of the largest relaxed galaxy clusters. Mon. Not. Roy. Astron. Soc. 353: 457
Alnes H., Amarzguioui M. and Gron O. (2006). An inhomogeneous alternative to dark energy?. Phys. Rev. D 73: 083519
Alnes H. and Amarzguioui M. (2007). The supernova Hubble diagram for off-center observers in a spherically symmetric inhomogeneous universe. Phys. Rev. D 75: 023506
Astier, P., et al.: [The SNLS Collaboration], The supernova legacy survey: measurement of Omega M , Omega Lambda and w from the first year data set. Astron. Astrophys. 447, 31 (2006)
Bahcall N., Ostriker J.P., Perlmutter S. and Steinhardt P.J. (1999). The cosmic triangle: revealing the state of the universe. Science 28: 1481
Barris, B.J., et al.: 23 high redshift supernovae from the IfA deep survey: doubling the SN sample at z > 0.7. Astrophys. J. 602, 571 (2004)
Biswas, T., Mansouri, R., Notari, A.: Nonlinear structure formation and apparent acceleration: an investigation. arXiv:astro-ph/0606703
Blanchard A., Douspis M., Rowan-Robinson M. and Sarkar S. (2003). An alternative to the cosmological ‘concordance model’. Astron. Astrophys. 412: 35
Blanchard A., Douspis M., Rowan-Robinson M. and Sarkar S. (2006). Large-scale galaxy correlations as a test for dark energy. Astron. Astrophys. 449: 925
Bonamente M., Joy M.K., La Roque S.J., Carlstrom J.E., Reese E.D. and Dawson K.S. (2006). Measurement of the cosmic distance scale from Chandra X-ray imaging and Sunyaev–Zel’dovich Effect mapping of high redshift clusters of galaxies. Astrophys. J. 647: 25
Bond J.R., Crittenden R., Davis R.L., Efstathiou G. and Steinhardt P.J. (1994). Measuring cosmological parameters with cosmic microwave background experiments. Phys. Rev. Lett. 72: 13
Bond J.R., Efstathiou G. and Tegmark M. (1997). Forecasting cosmic parameter errors from microwave background anisotropy experiments. Mon. Not. Roy. Astron. Soc. 291: L33
Carroll S.M., Press W.H. and Turner E.L. (1992). The cosmological constant. Ann. Rev. Astron. Astrophys. 30: 499
Cayrel, R., et al.: Measurement of stellar age from uranium decay. Nature 409, 691 (2001)
Celerier M.N. (2000). Do we really see a cosmological constant in the supernovae data?. Astron. Astrophys. 353: 63
Choudhury T.R. and Padmanabhan T. (2005). A theoretician’s analysis of the supernova data and the limitations in determining the nature of dark energy II: Results for latest data. Astron. Astrophys. 429: 807
Cole, S., et al.: [The 2dFGRS Collaboration], The 2dF galaxy redshift survey: power-spectrum analysis of the final dataset and cosmological implications. Mon. Not. Roy. Astron. Soc. 362, 505 (2005)
Conley, A. Carlberg, R.G., Guy, J., Howell, D.A., Jha, S., Riess, A.G., Sullivan, M.: Is there evidence for a Hubble bubble? The nature of SN Ia colors and dust in external galaxies. arXiv:0705.0367 [astro-ph]
Cooray A. and Caldwell R.R. (2006). Large-scale bulk motions complicate the Hubble Diagram. Phys. Rev. D 73: 103002
Copeland E.J., Sami M. and Tsujikawa S. (2006). Dynamics of dark energy. Int. J. Mod. Phys. D 15: 1753
Cyburt R.H., Fields B.D., Olive K.A. and Skillman E. (2005). New BBN limits on physics beyond the Standard Model from He-4. Astropart. Phys. 23: 313
de Bernardis, P., et al.: [Boomerang Collaboration], A flat universe from high-resolution maps of the cosmic microwave background radiation. Nature 404, 955 (2000)
Douglas M.R. and Kachru S. (2007). Flux compactification. Rev. Mod. Phys. 79: 733
Drell P.S., Loredo T.J. and Wasserman I. (2000). Type Ia supernovae, evolution, and the cosmological constant. Astrophys. J. 530: 593
Drexlin, G.: [KATRIN Collaboration], KATRIN: Direct measurement of a sub-eV neutrino mass. Nucl. Phys. Proc. Suppl. 145, 263 (2005)
Efstathiou G. and Bond J.R. (1999). Cosmic confusion: degeneracies among cosmological parameters derived from measurements of microwave background anisotropies. Mon. Not. Roy. Astron. Soc. 304: 75
Einstein, A.: Sitzungsber. Preuss. Akad. Wiss. phys.-math. Klasse VI 142 (1917)
Eisenstein, D.J., et al.: [SDSS Collaboration], Detection of the baryon acoustic peak in the large-scale correlation function of SDSS luminous red galaxies. Astrophys. J. 633, 560 (2005)
Elgaroy O. and Lahav O. (2003). The role of priors in deriving upper limits on neutrino masses from the 2dFGRS and WMAP. JCAP 0304: 004
Enqvist K. and Mattsson T. (2007). The effect of inhomogeneous expansion on the supernova observations. JCAP 0702: 019
Fields, B., Sarkar, S.: Big-bang nucleosynthesis (PDG mini-review). arXiv:astro-ph/0601514
Freedman, W.L., et al.: Final results from the Hubble Space Telescope Key Project to measure the Hubble constant. Astrophys. J. 55, 47 (2001)
Frith W.J., Metcalfe N. and Shanks T. (2006). New H-band galaxy number counts: a large local hole in the galaxy distribution?. Mon. Not. Roy. Astron. Soc. 371: 1601
Geller M.J. and Huchra J.P. (1989). Mapping the universe. Science 246: 897
Hanany, S., et al.: MAXIMA-1: A measurement of the cosmic microwave background anisotropy on angular scales of 10 arcminutes to 5 degrees. Astrophys. J. 545, L5 (2000)
Hillebrandt W. and Niemeyer J.C. (2000). Type Ia supernova explosion models. Ann. Rev. Astron. Astrophys. 38: 191
Hu W., Sugiyama N. and Silk J. (1997). The physics of microwave background anisotropies. Nature 386: 37
Hui L. and Greene P.B. (2006). Correlated fluctuations in luminosity distance and the importance of peculiar motion in supernova surveys. Phys. Rev. D 73: 123526
Hunt, P., Sarkar, S.: Multiple inflation and the WMAP ‘glitches’ II. Data analysis and cosmological parameter extraction. arXiv:0706.2443 [astro-ph]
Inoue K.T. and Silk J. (2006). Local voids as the origin of large-angle cosmic microwave background anomalies. Astrophys. J. 648: 23
Jackson, N.: The Hubble constant. arXiv:0709.3924 [astro-ph]
Jena, T., et al.: A concordance model of the Lyman-alpha Forest at z = 1.95. Mon. Not. Roy. Astron. Soc. 361, 70 (2005)
Jha S., Riess A.G. and Kirshner R.P. (2007). Improved distances to Type Ia supernovae with Multicolor Light Curve Shapes: MLCS2k2. Astrophys. J. 659: 122
Jungman G., Kamionkowski M., Kosowsky A. and Spergel D.N. (1996). Cosmological parameter determination with microwave background maps. Phys. Rev. D 54: 1332
Kochanek C.S. and Schechter P.L. (2004). The Hubble constant from gravitational lens time delays. In: Freedman, W. (eds) Measuring and Modeling the Universe, pp 117. Cambridge University Press, Cambridge
Koyama, K.: Ghosts in the self-accelerating universe. arXiv:0709.2399 [hep-th]
Krasinski A. (1997). Inhomogeneous Cosmological Models. Cambridge University Press, Cambridge
Krauss L.M. and Chaboyer B. (2003). Age estimates of globular clusters in the Milky Way: constraints on cosmology. Science 299: 65
Leibundgut B. (2000). Type Ia Supernovae. Astron. Astrophys. Rev. 10: 179
Lue A. (2006). The phenomenology of Dvali-Gabadadze-Porrati cosmologies. Phys. Rept. 423: 1
McClure M.L. and Dyer C.C. (2007). Anisotropy in the Hubble constant as observed in the HST extragalactic distance scale Key Project results. New Astron. 12: 533
Nobbenhuis S. (2006). Categorizing different approaches to the cosmological constant problem. Found. Phys. 36: 613
Padmanabhan T. (2003). Cosmological constant: the weight of the vacuum. Phys. Rept. 380: 235
Peebles, P.J.E.: The cosmological tests. astro-ph/0102327
Peebles P.J.E. and Ratra B. (2003). The cosmological constant and dark energy. Rev. Mod. Phys. 75: 559
Perlmutter, S., et al.: [Supernova Cosmology Project Collaboration], Measurements of Omega and Lambda from 42 high-redshift supernovae. Astrophys. J. 517, 565 (1999)
Reese, E.D.: Measuring the Hubble constant with the Sunyaev–Zeldovich effect. In: Freedman, W. (ed.) Measuring and Modeling the Universe, p. 138. Cambridge University Press, Cambridge (2004)
Riess, A.G., et al.: [Supernova Search Team Collaboration], Observational evidence from supernovae for an accelerating universe and a cosmological constant. Astron. J. 116, 1009 (1998)
Riess, A.G., et al.: [Supernova Search Team Collaboration], Type Ia supernova discoveries at z > 1 from the Hubble Space Telescope: evidence for past deceleration and constraints on dark energy evolution. Astrophys. J. 607, 665 (2004)
Rowan-Robinson, M.: Cosmological parameters: do we already know the final answer? In: Spooner, N., Kudryavtsev, V. (eds.) Third International Conference on Identification of Dark Matter. World Scientific, Singapore (2001)
Rowan-Robinson M. (2002). Do type Ia supernovae prove Lambda > 0?. Mon. Not. Roy. Astron. Soc. 332: 352
Rudnick, L., Brown, S., Williams, L.R.: Extragalactic radio sources and the WMAP cold spot. arXiv:0704.0908 [astro-ph]
Saha P., Coles J., Maccio A.V. and Williams L.L.R. (2006). The Hubble time inferred from 10 time-delay lenses. Astrophys. J. 650: L17
Sahni V. and Starobinsky A.A. (2000). The case for a positive cosmological Lambda-term. Int. J. Mod. Phys. D 9: 373
Sandage M.A., Tammann G.A., Saha A., Reindl B., Macchetto F.D. and Panagia N. (2006). The Hubble constant: a summary of the HST program for the luminosity calibration of Type Ia supernovae by means of cepheids. Astrophys. J. 653: 843
Schwarz, D.J., Weinhorst, B.: (An)isotropy of the Hubble diagram: comparing hemispheres. arXiv:0706.0165 [astro-ph]
Spergel D.N., et al.: [WMAP Collaboration], First year Wilkinson Microwave Anisotropy Probe observations: determination of cosmological parameters. Astrophys. J. Suppl. 148, 175 (2003)
Spergel, D.N., et al.: [WMAP Collaboration], Wilkinson Microwave Anisotropy Probe three year results: implications for cosmology. Astrophys. J. Suppl. 170, 377 (2007)
Straumann, N.: On the cosmological constant problems and the astronomical evidence for a homogeneous energy density with negative pressure. In: Duplantier, B., Rivasseu, V. (eds.) Séminaire Poincaré: Vacuum Energy—Renormalization, p. 7. Birkhäuser-Verlag, Basel (2003)
Tegmark, M., et al.: [SDSS Collaboration], The 3D power spectrum of galaxies from the SDSS. Astrophys. J. 606, 702 (2004)
Tegmark M., Aguirre A., Rees M. and Wilczek F. (2006). Dimensionless constants, cosmology and other dark matters. Phys. Rev. D 73: 023505
Tomita K. (2000). Bulk flows and cosmic microwave background dipole anisotropy in cosmological void models. Astrophys. J. 529: 26
Tomita K. (2001). Anisotropy of the Hubble constant in a cosmological model with a local void on scales of 200 Mpc. Prog. Theor. Phys. 105: 419
Tomita K. (2001). A local void and the accelerating universe. Mon. Not. Roy. Astron. Soc. 326: 287
Tomita K. (2001). Analyses of Type Ia Supernova data in cosmological models with a local void. Prog. Theor. Phys. 106: 929
Tomita K. (2003). Dipole anisotropies of IRAS galaxies and the contribution of a large-scale local void. Astrophys. J. 584: 580
Tonry J.L., et al.: [Supernova Search Team Collaboration], Cosmological results from high-z supernovae. Astrophys. J. 594, 1 (2003)
Van Waerbeke L., Mellier Y. and Hoekstra H. (2005). Dealing with systematics in cosmic shear studies: new results from the VIRMOS-Descart survey. Astron. Astrophys. 429: 75
Wang Y., Spergel D.N. and Turner E.L. (1998). Implications of cosmic microwave background anisotropies for large scale variations in Hubble’s constant. Astrophys. J. 498: 1
Wood-Vasey, W.M., et al.: Observational constraints on the nature of the dark energy: first cosmological results from the ESSENCE supernova survey. Astrophys. J. L666, 694 (2007)
Weinberg S. (1989). The cosmological constant problem. Rev. Mod. Phys. 61: 1
Weinberg, S.: Theories of the cosmological constant. In: Cline D. (ed.) Sources and detection of dark matter and dark energy in the universe. Springer, Berlin, p. 18 (2000)
Weinberg S. (2000). A priori probability distribution of the cosmological constant. Phys. Rev. D 61: 103505
Witten, E.: The cosmological constant from the viewpoint of string theory. In: Cline, D. (ed.) Sources and detection of dark matter and dark energy in the universe, p. 27. Springer, Berlin (2000)
Yao, W.M., et al.: [Particle Data Group], Review of particle physics. J. Phys. G 33, 1 (2006)
Zehavi I., Riess A.G., Kirshner R.P. and Dekel A. (1998). A local Hubble bubble from SNe Ia?. Astrophys. J. 503: 483
Zwirner, F.: Extensions of the standard model. In: International europhysics conference on high energy physics, Brussels, p. 943. World Scientific, Singapore (1996)
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Sarkar, S. Is the evidence for dark energy secure?. Gen Relativ Gravit 40, 269–284 (2008). https://doi.org/10.1007/s10714-007-0547-7
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DOI: https://doi.org/10.1007/s10714-007-0547-7