Finslerian dipolar modulation of the CMB power spectra at scales 
                $$2&lt;l&lt;600$$
                
                    
                                    
                        
                            2
                            &lt;
                            l
                            &lt;
                            600

Li, Xin; Lin, Hai-Nan

doi:10.1140/epjc/s10052-017-4897-3

Cited by 12 publications

(22 citation statements)

References 52 publications

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“…This way we take into account the entire light curve and not just parts of it around the critical phases. This method was applied by Derekas et al (2012) when they detected the random period jitter of a Cepheid (V1154 Cyg), and also by Li & Qian (2014) and Guggenberger & Steixner (2015) who search for potential light-time effect caused by a companion in the Kepler RR Lyrae sample. This work used the same implementation of the method what we used in Benkő et al (2016), namely the program of Derekas et al (2012) sligthly adjusted to RR Lyrae stars.…”

Section: The O−c Diagramsmentioning

confidence: 99%

“…The appearance of the Kepler year in the flux data has already been known (Bányai et al 2013) but here we demonstrated that this instrumental systematics affects the phases. Li & Qian (2014) identified the long periodicities in the O−C diagrams of FN Lyr and V894 Lyr, using the Kepler data, as potential light-time effect caused by companions. As we can see in Tab.…”

Section: Fourier Analysis Of the O−c Diagramsmentioning

confidence: 99%

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Revisiting the Kepler non-Blazhko RR Lyrae sample: cycle-to-cyle variations and additional modes

Benkő

Jurcsik

Derekas

2019

Monthly Notices of the Royal Astronomical Society

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We analyzed the long and short cadence light curves of the Kepler non-Blazhko RRab stars. We prepared the Fourier spectra, the Fourier amplitude and phase variation functions, time-frequency representation, the O−C diagrams and their Fourier contents. Our main findings are: (i) All stars which are brighter a certain magnitude limit show significant cycle-to-cycle light curve variations. (ii) We found permanently excited additional modes for at least one third of the sample and some other stars show temporarily excited additional modes. (iii) The presence of the Blazhko effect was carefully checked and identified one new Blazhko candidate but for at least 16 stars the effect can be excluded. This fact has important consequences. Either the cycle-tocycle variation phenomenon is independent from the Blazhko effect and the Blazhko incidence ratio is still much lower (51%-55%) than the extremely large (>90%) ratio published recently. The connection between the extra modes and the cycle-to-cycle variations is marginal.

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Section: The O−c Diagramsmentioning

confidence: 99%

Section: Fourier Analysis Of the O−c Diagramsmentioning

confidence: 99%

Revisiting the Kepler non-Blazhko RR Lyrae sample: cycle-to-cyle variations and additional modes

Benkő

Jurcsik

Derekas

2019

Monthly Notices of the Royal Astronomical Society

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“…In Finsler space-time, the gravitational field equation takes the form (Li & Chang 2014;Li et al 2015b;Li & Lin 2017)…”

Section: The Comoving Curvature Perturbation In Finsler Space-timementioning

confidence: 99%

“…As a special case of Finsler geometry, Randers space has been used to study the anisotropic inflation (Li et al 2015b;Li & Wang 2016;Li & Lin 2017) and the anisotropic accelerating expansion of the universe (Li et al 2015a). For the background space-time, the Finsler structure in this work is given by…”

Section: The Comoving Curvature Perturbation In Finsler Space-timementioning

confidence: 99%

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Finsler space–time can explain both parity asymmetry and power deficit seen in CMB temperature anisotropies

Chang

Rath

Sang

et al. 2018

Monthly Notices of the Royal Astronomical Society

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We propose a framework of Finsler space-time to explain the observed parity asymmetry and the power deficit in the low-ℓ (2 ℓ 29) multipole range of cosmic microwave background (CMB) temperature anisotropies. In the 3 + 1 dimensional space-time, the three-dimensional space is described by a Randers-Finsler space, which is spatially irreversible, inducing the parity asymmetry in the CMB angular power spectrum. We estimate the constraints on the two parameters introduced by Finsler space-time via analyzing the low-ℓ angular power spectrum in PLANCK 2015 CMB temperature data. We see that the low-ℓ power suppression in the CMB temperature anisotropies can also be resolved in this scenario. Our study shows that the two low-ℓ anomalies, i.e., parity asymmetry and power deficit, may have a common origin.

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Isotropy statistics of CMB hot and cold spots

Khan

Saha

2022

J. Cosmol. Astropart. Phys.

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Statistical Isotropy of the Cosmic Microwave Background (CMB) radiation has been studied and debated extensively in recent years. Under this assumption, the hot spots and cold spots of the CMB are expected to be uniformly distributed over a 2-sphere. We use the orientation matrix, first proposed by Watson (1965) and Scheidegger (1965) and associated shape and strength parameters (Woodcock, 1977) to analyse whether the hot and cold spots of the observed CMB temperature anisotropy field are uniformly placed. We demonstrate the usefulness of our estimators by using simulated toy models containing non-uniform data. We apply our method on several foreground minimized CMB maps observed by WMAP and Planck over large angular scales. The shape and strength parameters constrain geometric features of possible deviations from uniformity (isotropy) and the power of the anomalous signal. We find that distributions of hot or cold spots in cleaned maps show no unusual signature of clustering or girdling. Instead, we notice a strikingly uniform distribution of hot spots over the full sky. The signal remains robust with respect to the four cleaned maps used and presence or absence of the non-Gaussian cold spot (NGCS). On the partial sky with WMAP KQ75 and Planck U73 masks we find anomalously low strength of non-uniformity for cold spots which is found to be robust with respect to various cleaning methods, masks applied, instruments, frequencies, and the presence or absence of the NGCS. Interestingly we find that the signal of anomalously weak non-uniformity could be due to contributions from the quadrupole and octupole and may be related with the low CMB temperature variance anomaly.

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Finslerian dipolar modulation of the CMB power spectra at scales $$2<l<600$$ 2 < l < 600

Cited by 12 publications

References 52 publications

Revisiting the Kepler non-Blazhko RR Lyrae sample: cycle-to-cyle variations and additional modes

Revisiting the Kepler non-Blazhko RR Lyrae sample: cycle-to-cyle variations and additional modes

Finsler space–time can explain both parity asymmetry and power deficit seen in CMB temperature anisotropies

Isotropy statistics of CMB hot and cold spots

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