Data Analysis in Cosmology

Martı́nez, Vicent J.; Saar, E.; Gonzales, Enrique Martinez; Pons-Bordería, M. J.

doi:10.1007/978-3-540-44767-2

Cited by 27 publications

(3 citation statements)

References 130 publications

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“…However, in CMB polarization experiments, the energy scale cannot be conclusively determined because there is a degeneracy between E and B modes via the first slow-roll parameter 1 (equation (4.4)), which can only be sorted out once r is measured conclusively. But B-mode polarized states can be contaminated with cosmic strings, primordial magnetic field, etc, thereby making it difficult to measure r conclusively (for a lucid discussion see [43]). So, the cosmological Berry phase may have the potentiality to play some important role in inflationary cosmology, since it is related to r and V via equations (4.9) and (4.10).…”

Section: Physical Significance Of Cosmological Berry Phasementioning

confidence: 99%

The Berry phase in inflationary cosmology

Pal

Basu

2013

Class. Quantum Grav.

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We derive an analogue of the Berry phase associated with inflationary cosmological perturbations of quantum mechanical origin by obtaining the corresponding wavefunction. We have further shown that cosmological Berry phase can be completely envisioned through the observable parameters, viz. spectral indices. Finally, physical significance of this phase is discussed from the point of view of theoretical and observational aspects with some possible consequences of this quantity in inflationary cosmology.

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Section: Physical Significance Of Cosmological Berry Phasementioning

confidence: 99%

The Berry phase in inflationary cosmology

Pal

Basu

2013

Class. Quantum Grav.

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“…A wavelet ψ(t) (Farge 1992;Flandrin 1992;Wojtaszczyk 1997;Torrence & Compo 1998;Addison 2002;Mallat 2009;Martínez et al 2009;Kirby & Swain 2013) is a short, temporaly and spectraly localized oscillation with finite energy (i.e., normalized in the L 2 norm, ψ(t), ψ(t) = 1) and zero mean 6 , ψ(t) = 0. A mother wavelet generates the dictionary, or child wavelets, forming the basis:…”

Section: Waveletsmentioning

confidence: 99%

A comprehensive power spectral density analysis of astronomical time series I: the Fermi-LAT gamma-ray light curves of selected blazars

Tarnopolski,

Żywucka,

Marchenko

et al. 2020

Preprint

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We present the results of the Fermi -LAT 10-years-long light curves (LCs) modeling of selected blazars: six flat spectrum radio quasars (FSRQs) and five BL Lacertae (BL Lacs), examined in 7-, 10-, and 14-day binning. The LCs and power spectral densities (PSDs) were investigated with various methods: Fourier transform, Lomb-Scargle periodogram (LSP), wavelet scalogram, autoregressive moving average (ARMA) process, continuous-time ARMA (CARMA), Hurst exponent (H), and the A − T plane. First, with extensive simulations we showed that parametric modeling returns unreliable parameters, with a high dispersion for different realizations of the same stochastic model. Hence any such analysis should be supported with Monte Carlo simulations. For our blazar sample, we find that the power law indices β calculated from the Fourier and LSP modeling mostly fall in the range 1 β 2. Using the wavelet scalograms, we confirm a quasi-periodic oscillation (QPO) in PKS 2155−304 at a 3σ significance level, but do not detect any QPOs in other objects. The ARMA fits reached higher orders for 7-day binned LCs and lower orders for 10-and 14-days binned LCs for the majority of blazars, suggesting there might exist a characteristic timescale for the perturbations in the jet and/or accretion disk to die out. ARMA and CARMA modeling revealed breaks in their PSDs at timescales of few hundred days. The estimation of H was performed with several methods. We find that most blazars exhibit H > 0.5, indicating long-term memory. Finally, the FSRQ and BL Lac subclasses are clearly separated in the A − T plane.

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“…As science and technology advance, observations can be made accurately and the universe and the nature of the universe can be more accurately explained, for example by using the WMAPs telescope, researchers could understand the structure of the universe better than before (Martinez, 2009). By using the Hubble telescope, researchers could explain the origin of the universe which started from the instant which is called the Big Bang (Bortz, 2013).…”

Section: Literature Reviewmentioning

confidence: 99%

The Compatibility between the Quran and Modern Science: A Comparative Study among Malaysian

Kasmo¹,

Usman²,

Haron³

et al. 2015

ASS

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The paper reports a study which was conducted among 644 respondents from the age of 20 to the age of 55 in Malaysia. The respondents, male and female were obtained randomly throughout the country, from different ethnic and religious backgrounds. The respondents were given booklet of questionnaire containing statements about the relation between the Quran and science. The statements were provided with responses in the form of Likert scale ranging from 1. The data was analysed to obtain the mean, percentages, and the difference of means were tested using the t-test and one-Way ANOVA. The results of the study show that 66.9% of the respondents accepted the statement that the Quran is compatible with modern science. 12.6% rejected the statement and 20.5% was not sure. There were difference of means of the responses of the respondents based on their religion and the difference of mean was significant.

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Data Analysis in Cosmology

Cited by 27 publications

References 130 publications

The Berry phase in inflationary cosmology

The Berry phase in inflationary cosmology

A comprehensive power spectral density analysis of astronomical time series I: the Fermi-LAT gamma-ray light curves of selected blazars

The Compatibility between the Quran and Modern Science: A Comparative Study among Malaysian

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