Efficient Computation of Cosmic Microwave Background Anisotropies in Closed Friedmann‐Robertson‐Walker Models

Lewis, Antony; Challinor, A.; Lasenby, A.

doi:10.1086/309179

Cited by 4,947 publications

(5,413 citation statements)

References 20 publications

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“…When the flat prior on µ/m Pl lies in [0. 1,10], then the values p ≃ 2 are slightly disfavoured but this tendency completely disappears when the prior is extended to [0. 1,100].…”

Section: Small Field Modelsmentioning

confidence: 99%

“…Following [52], we used a modified version of the CAMB code [10] to compute the CMB temperature and polarisation anisotropies seeded by the slow-roll scalar and tensor primordial power spectra of equation (45). The parameter space has been sampled by using Markov Chain Monte Carlo (MCMC) methods implemented in the COSMOMC code [11] and using the likelihood estimator provided by the WMAP team [2,4,3,1].…”

Section: Wmap Data Constraints On the Slow-roll Parametersmentioning

confidence: 99%

“…As previously, the dotted black curves are the mean likelihoods, the thick solid black curves represent the marginalised probabilities obtained under a flat prior on the parameter µ/m Pl in the range [0. 1,10] and, finally, the thin solid red lines refer to the marginalised probability stemming from a flat prior on µ/m Pl but now in the range [0. 1,100].…”

Section: Small Field Modelsmentioning

confidence: 99%

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Inflation after WMAP3: confronting the slow-roll and exact power spectra with CMB data

Martin

Ringeval

2006

J. Cosmol. Astropart. Phys.

242

374

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Abstract.The implications of the WMAP (Wilkinson Microwave Anisotropy Probe) third year data for inflation are investigated using both the slow-roll approximation and an exact numerical integration of the inflationary power spectra including a phenomenological modelling of the reheating era. At slow-roll leading order, the constraints ǫ 1 < 0.022 and −0.07 < ǫ 2 < 0.07 are obtained at 95% CL (Confidence Level) implying a tensor-to-scalar ratio r 10 < 0.21 and a Hubble parameter during inflation H/m Pl < 1.3 × 10 −5 . At next-to-leading order, a tendency for ǫ 3 > 0 is observed. With regards to the exact numerical integration, large field models, V (φ) ∝ φ p , with p > 3.1 are now excluded at 95% CL. Small field models, V (φ) ∝ 1 − (φ/µ) p , are still compatible with the data for all values of p. However, if µ/m Pl < 10 is assumed, then the case p = 2 is slightly disfavoured. In addition, mild constraints on the reheating temperature for an extreme equation of state w reh −1/3 are found, namely T reh > 2 TeV at 95% CL. Hybrid models are disfavoured by the data, the best fit model having ∆χ 2 ≃ +5 with two extra parameters in comparison with large field models. Running mass models remain compatible, but no prior independent constraints can be obtained. Finally, superimposed oscillations of trans-Planckian origin are studied. The vanilla slow-roll model is still the most probable one. However, the overall statistical weight in favour of superimposed oscillations has increased in comparison with the WMAP first year data, the amplitude of the oscillations satisfying 2|x|σ 0 < 0.76 at 95% CL. The best fit model leads to an improvement of ∆χ 2 ≃ −12 for 3 extra parameters. Moreover, compared to other oscillatory patterns, the logarithmic shape is favoured.

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“…When the flat prior on µ/m Pl lies in [0. 1,10], then the values p ≃ 2 are slightly disfavoured but this tendency completely disappears when the prior is extended to [0. 1,100].…”

Section: Small Field Modelsmentioning

confidence: 99%

Section: Wmap Data Constraints On the Slow-roll Parametersmentioning

confidence: 99%

Section: Small Field Modelsmentioning

confidence: 99%

See 1 more Smart Citation

Inflation after WMAP3: confronting the slow-roll and exact power spectra with CMB data

Martin

Ringeval

2006

J. Cosmol. Astropart. Phys.

242

374

View full text Add to dashboard Cite

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“…1) have been calculated through a modified version of the CAMB 2 code (Lewis et al 2000). In particular, 10000 simulations have been generated with a resolution given by the HEALPix (Górski et al 2005) parameter NSIDE=64.…”

Section: Simulated Mapsmentioning

confidence: 99%

On the recovery of ISW fluctuations using large-scale structure tracers and CMB temperature and polarization anisotropies

Bonavera

Barreiro

Vielva

2016

Mon. Not. R. Astron. Soc.

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In this work we present a method to extract the signal induced by the integrated Sachs-Wolfe (ISW) effect in the cosmic microwave background (CMB). It makes use of the Linear Covariance-Based filter introduced by Barreiro et al., and combines CMB data with any number of large-scale structure (LSS) surveys and lensing information. It also exploits CMB polarization to reduce cosmic variance. The performance of the method has been thoroughly tested with simulations taking into account the impact of non-ideal conditions such as incomplete sky coverage or the presence of noise. In particular, three galaxy surveys are simulated, whose redshift distributions peak at low (z 0.3), intermediate (z 0.6) and high redshift (z 0.9). The contribution of each of the considered data sets as well as the effect of a mask and noise in the reconstructed ISW map is studied in detail. When combining all the considered data sets (CMB temperature and polarization, the three galaxy surveys and the lensing map), the proposed filter successfully reconstructs a map of the weak ISW signal, finding a perfect correlation with the input signal for the ideal case and around 80 per cent, on average, in the presence of noise and incomplete sky coverage. We find that including CMB polarization improves the correlation between input and reconstruction although only at a small level. Nonetheless, given the weakness of the ISW signal, even modest improvements can be of importance. In particular, in realistic situations, in which less information is available from the LSS tracers, the effect of including polarisation is larger. For instance, for the case in which the ISW signal is recovered from CMB plus only one survey, and taking into account the presence of noise and incomplete sky coverage, the improvement in the correlation coefficient can be as large as 10 per cent.

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“…[20] coupled to the CosmoMc (Cosmological Monte Carlo) code [21]. This code makes use of a Markov-chain Monte Carlo method to derive the likelihood values of model parameters.…”

Section: Likelihood Analysismentioning

confidence: 99%

Constraints on braneworld inflation from CMB anisotropies

Tsujikawa¹,

Liddle²

2004

J. Cosmol. Astropart. Phys.

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We obtain observational constraints on Randall-Sundrum type II braneworld inflation using a compilation of data including WMAP, the 2dF and latest SDSS galaxy redshift surveys. We place constraints on three classes of inflation models (large-field, small-field and hybrid models) in the high-energy regime, which exhibit different behaviour compared to the low-energy case. The quartic potential is outside the 2σ observational contour bound for a number of e-folds less than 60, and steep inflation driven by an exponential potential is excluded because of its high tensor-to-scalar ratio. It is more difficult to strongly constrain small-field and hybrid models due to additional freedoms associated with the potentials, but we obtain upper bounds for the energy scale of inflation and the model parameters in certain cases. We also discuss possible ways to break the degeneracy of consistency relations and inflationary observables.

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Efficient Computation of Cosmic Microwave Background Anisotropies in Closed Friedmann‐Robertson‐Walker Models

Cited by 4,947 publications

References 20 publications

Inflation after WMAP3: confronting the slow-roll and exact power spectra with CMB data

Inflation after WMAP3: confronting the slow-roll and exact power spectra with CMB data

On the recovery of ISW fluctuations using large-scale structure tracers and CMB temperature and polarization anisotropies

Constraints on braneworld inflation from CMB anisotropies

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