The location of cosmic microwave background peaks in a universe with dark energy

Doran, Michael; Lilley, Matthew

doi:10.1046/j.1365-8711.2002.05144.x

Cited by 81 publications

(118 citation statements)

References 15 publications

(32 reference statements)

Supporting

Mentioning

113

Contrasting

Order By: Relevance

“…Practically the same information is contained in a few characteristics such as the amplitude and inclination of the power spectrum at COBE scale and the amplitudes and locations of the observed acoustic peaks and dips. Indeed, it was shown (see Hu & Sugiyama 1995;Hu & White 1996;Efstathiou & Bond 1999;Doran & Lilley 2002 and references therein) that the sensitivity of the locations and amplitudes of the extrema, especially of the peaks, to cosmological parameters is the same as their sensitivity to the flat band powers, the C l values, from presently available data. This is not surprising: the extrema have an obvious physical interpretation and have the largest weight among data points on the CMB power spectrum as a result of a minimal ratio of error to value.…”

Section: Introductionmentioning

confidence: 98%

Acoustic Peaks and Dips in the Cosmic Microwave Background Power Spectrum: Observational Data and Cosmological Constraints

Durrer¹,

Novosyadlyj²,

Apunevych³

2003

ApJ

View full text Add to dashboard Cite

The locations and amplitudes of three acoustic peaks and two dips in the BOOMERANG, MAXIMA, and DASI measurements of the cosmic microwave background (CMB) anisotropy power spectra as well as their statistical confidence levels are determined in a model-independent way. It is shown that the BOOMERANG 2001 data from Netterfield and coworkers fix the location and amplitude of the first acoustic peak at more than 3 confidence. The next two peaks and dips are determined at a confidence level above 1 but below 2 . The locations and amplitudes of the first three peaks and two dips are l p 1 ¼ 212 AE 17,(1 errors include statistical and systematic errors). The MAXIMA and DASI experiments give similar values for the extrema that they determine. For MAXIMA these are the first and third peaks, for DASI the first and second peaks and the first dip. Moreover, the locations and amplitudes of the extrema determined from the combined data of all experiments are quite close to the corresponding values extracted from the BOOMERANG data alone. In order to use these data in a fast search for cosmological parameters, an accurate analytic approximation to calculate CMB peak and dip positions and amplitudes in mixed dark matter models with cosmological constant and curvature is derived and tested. The determined cosmological parameters from the CMB acoustic extrema data show good agreement with other determinations, especially with the baryon content as deduced from standard nucleosynthesis constraints, as shown by Burles and coworkers. These data supplemented by constraints from direct measurements of some cosmological parameters and data on large-scale structure lead to a best-fit model that agrees with practically all the used experimental data within 1 . The best-fit parameters are Ã ¼ 0

show abstract

Section: Introductionmentioning

confidence: 98%

Acoustic Peaks and Dips in the Cosmic Microwave Background Power Spectrum: Observational Data and Cosmological Constraints

Durrer¹,

Novosyadlyj²,

Apunevych³

2003

ApJ

View full text Add to dashboard Cite

show abstract

“…One of the features of this model is the variation of equation of state during the expansion of the universe. Various Quintessence models like k-essence [10], tachyonic matter [11], Phantom [12,13] and Chaplygin gas [14] provide various equations of states for the dark energy [13,14,15,16,17,18,19,20,21].…”

mentioning

confidence: 99%

Observational Constraints with Recent Data on the DGP Modified Gravity

2008

View full text Add to dashboard Cite

We study one of the simplest covariant modified-gravity models based on the Dvali-Gabadadze-Porrati (DGP) brane cosmology, a self-accelerating universe. In this model gravitational leakage into extra dimensions is responsible of late-time acceleration. We mainly focus on the effects of the model parameters on the geometry and the age of universe. Also we investigate the evolution of matter density perturbations in the modified gravity model, and obtain an analytical expression for the growth index, f . We show that increasing Ωr c leads to less growth of the density contrast δ, and also decreases the growth index. We give a fitting formula for the growth index at the present time and indicate that dominant term in this expression verifies the well-known approximation relation f ≃ Ω γ m . As the observational test, the new Supernova Type Ia (SNIa) Gold sample and Supernova Legacy Survey (SNLS) data, size of baryonic acoustic peak from Sloan Digital Sky Survey (SDSS), the position of the acoustic peak from the CMB observations and the Cluster Baryon Gas Mass Fraction (gas) are used to constrain the parameters of the DGP model. We also combine previous results with large scale structure formation (LSS) from the 2dFGRS survey. Finally to check the consistency of the DGP model, we compare the age of old cosmological objects with age of universe in this model.

show abstract

“…Driving effects from the decay of the gravitational potential as well as contributions from the Doppler shift of the oscillating fluid introduce a shift in the spectrum. A good parameterization for the location of the peaks and troughs is given by [40,41] …”

Section: B Cmbr Shift Parametermentioning

confidence: 99%

“…The location of first acoustic peak can be determined in model by equation (39) with φ 1 (ω m , ω b ) ≃ 0.27 [40,41]. It is easily shown that shift parameter is as follows [42]:…”

Section: B Cmbr Shift Parametermentioning

confidence: 99%

See 1 more Smart Citation

Consistency off(R)=R2−R02gravity with cosmological observations in the Palatini formalism

2007

View full text Add to dashboard Cite

In this work we study the dynamics of universe in f (R) = R 2 − R 2 0 modified gravity with Palatini formalism. We use data from recent observations as Supernova Type Ia (SNIa) Gold sample and Supernova Legacy Survey (SNLS) data, size of baryonic acoustic peak from Sloan Digital Sky Survey (SDSS), the position of the acoustic peak from the CMB observations and large scale structure formation (LSS) from the 2dFGRS survey to put constraint on the parameters of the model. To check the consistency of this action, we compare the age of old cosmological objects with the age of universe. In the combined analysis with the all the observations, we find the parameters of model as R0 = 6.192 [1,2]. Analysis of SNIa and the Cosmic Microwave Background radiation (CMB) observations indicates that about 70% of the total energy of the Universe is made by the dark energy and the rest of it is in the form of dark matter with a few percent of Baryonic matter [3][4][5]. The "cosmological constant" is a possible explanation of the present dynamics of the universe [6]. This term in Einstein field equations can be regarded as a fluid with the equation of state of w = −1. However, there are two problems with the cosmological constant, namely the fine-tuning and the cosmic coincidence. In the framework of quantum field theory, the vacuum expectation value is 123 order of magnitude larger than the observed value of 10 −47 GeV 4 . The absence of a fundamental mechanism which sets the cosmological constant to zero or to a very small value is the cosmological constant problem. The second problem known as the cosmic coincidence, states that why are the energy densities of dark energy and dark matter nearly equal today?There are various solutions for this problem as the decaying cosmological constant models. A non-dissipative minimally coupled scalar field, so-called Quintessence can play the role of this time varying cosmological constant [7][8][9]. The ratio of energy density of this field to the matter density in this model increases by the expansion of the universe and after a while dark energy becomes the dominant term of the energy-momentum tensor. Another approach dealing with this problem is using the modified gravity by changing the Einstein-Hilbert action. Recently a great attention has been devoted to this era because of the prediction of early and late time accelerations in these models [22]. While it seems that the modified gravity and dark energy models are completely different approaches to explain cosmic acceleration, it is possible to unify them in one formalism [23].In this work we obtain the dynamics of the modified gravity f (R) = R 2 − R 2 0 in the Palatini formalism [24] and use the cosmological observations as SNIa, SDSS acoustic peck in CMB and structure formation to put constraint on the parameter of the action. In Sec. II we derive the dynamics of Hubble parameter and scale factor in Palatini formalism for general case of f (R) gravity. In Sec. III using action f (R) = R 2 − R 2 0 we obtain the dynamics of univers...

show abstract

The location of cosmic microwave background peaks in a universe with dark energy

Cited by 81 publications

References 15 publications

Acoustic Peaks and Dips in the Cosmic Microwave Background Power Spectrum: Observational Data and Cosmological Constraints

Acoustic Peaks and Dips in the Cosmic Microwave Background Power Spectrum: Observational Data and Cosmological Constraints

Observational Constraints with Recent Data on the DGP Modified Gravity

Consistency off(R)=R2−R02gravity with cosmological observations in the Palatini formalism

Contact Info

Product

Resources

About