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The cosmic microwave background (CMB) offers a unique window into the early universe, providing insights into cosmological parameters like the Hubble constant. Recent precise measurements of the CMB by experiments like Planck seem to point…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-26 Pablo Lemos , Paul Shah

We present a new constraint on the effective number of relativistic species in the early universe, $N_{\rm eff}$, by combining recent primordial helium abundance measurements from the Large Binocular Telescope $Y_p$ Project with primordial…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-23 Samuel Goldstein , J. Colin Hill

We studied a constraint on the primordial helium abundance Y_p from current and future observations of CMB. Using the currently available data from WMAP, ACBAR, CBI and BOOMERANG, we obtained the constraint as Y_p = 0.25^{+0.10}_{-0.07} at…

Astrophysics · Physics 2008-11-26 Kazuhide Ichikawa , Toyokazu Sekiguchi , Tomo Takahashi

We calculate temperature anisotropies of the cosmic microwave background (CMB) for several initial power spectra of density perturbations with a built-in scale suggested by recent optical data on the spatial distribution of rich clusters of…

Astrophysics · Physics 2009-10-30 F. Atrio-Barandela , J. Einasto , S. Gottlöber , V. Müller , A. A. Starobinsky

In this paper, we study the cosmological constraints from the measurements of Hubble parameters---$H(z)$ data. Here, we consider two kinds of $H(z)$ data: the direct $H_0$ probe from the Hubble Space Telescope (HST) observations of Cepheid…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-31 Wei Zheng , Hong Li , Jun-Qing Xia , You-Ping Wan , Si-Yu Li , Mingzhe Li

We focus on viable $f(T)$ teleparallel cosmological models, namely power law, exponential and square-root exponential, carrying out a detailed study of their evolution at all scales. Indeed, these models were extensively analysed in the…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-10 Micol Benetti , Salvatore Capozziello , Gaetano Lambiase

The recently constructed Hubble diagram using a combined sample of SNLS and SDSS-II Type Ia SNe, and an application of the Alcock-Paczynski (AP) test using model-independent Baryon Acoustic Oscillation data, have suggested that the…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-25 Fulvio Melia , Thomas M. McClintock

In this paper we compare data to theory. We use a compilation of the most recent cosmic microwave background (CMB) measurements to constrain Hubble's constant h, the baryon fraction Omega_b, and the cosmological constant lambda. We fit h-,…

Astrophysics · Physics 2008-02-03 Charles H. Lineweaver , Domingos Barbosa , Alain Blanchard , James G. Bartlett

A cosmic lepton asymmetry $\eta_{\text{l}}=(n_{\text{l}}-n_{\bar{\text{l}}})/n_{\gamma}$ affects the primordial helium abundance and the expansion rate of the early Universe. Both of these effects have an impact on the anisotropies of the…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-25 Isabel M. Oldengott , Dominik J. Schwarz

The Cosmic Microwave Background (CMB) is a fundamental observational tool in modern cosmology. The linear polarization of the CMB provides a crucial observational tool for exploring new physics, including the inflationary paradigm and…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-12 Vyoma Muralidhara

There is solid theoretical and observational motivation behind the idea of scale-invariance as a fundamental symmetry of Nature. We consider a recently proposed classically scale-invariant inflationary model, quadratic in curvature and…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-25 Chiara Cecchini , Mariaveronica De Angelis , William Giarè , Massimiliano Rinaldi , Sunny Vagnozzi

We present new limits on the amplitude of potential primordial magnetic fields (PMFs) using temperature and polarization measurements of the cosmic microwave background (CMB) from Planck, BICEP2/Keck Array, POLARBEAR, and SPTpol. We reduce…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-20 Dylan R. Sutton , Chang Feng , Christian L. Reichardt

Big Bang Nucleosynthesis (BBN) relates key cosmological parameters to the primordial abundance of light elements. In this paper, we point out that the recent observations of Cosmic Microwave Background anisotropies by the Planck satellite…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-06 Eleonora Di Valentino , Carlo Gustavino , Julien Lesgourgues , Gianpiero Mangano , Alessandro Melchiorri , Gennaro Miele , Ofelia Pisanti

The CMB temperature power spectrum offers ambiguous evidence for the existence of horizon-scale power in the primordial power spectrum due to uncertainties in spatial curvature and the physics of cosmic acceleration as well as the observed…

Cosmology and Nongalactic Astrophysics · Physics 2009-07-30 Michael J. Mortonson , Wayne Hu

Many inflation models predict that primordial density perturbations have a nonzero three-point correlation function, or bispectrum in Fourier space. Of the several possibilities for this bispectrum, the most commmon is the local-model…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-01 Razieh Emami , Emanuela Dimastrogiovanni , Jens Chluba , Marc Kamionkowski

We present independent determinations of cosmological parameters using the distance estimator based on the established correlation between the Balmer line luminosity, L(H$\beta$), and the velocity dispersion ($\sigma$) for HII galaxies…

We propose a new analysis of small scale CMB data by introducing the cosmological dependency of the foreground signals, focusing first on the thermal Sunyaev-Zel'dovich (tSZ) power spectrum, derived from the halo model. We analyse the…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-22 Marian Douspis , Laura Salvati , Adélie Gorce , Nabila Aghanim

The current most accepted paradigm for the early universe cosmology, the inflationary scenario, shows a good agreement with the recent Cosmic Microwave Background (CMB) and polarization data. However, when the inflation consistency relation…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-20 L. L. Graef , M. Benetti , J. S. Alcaniz

Extensive recent work on the Sunyaev-Zeldovich (S-Z) effect reflects major progress in observational capabilities of interferometric arrays, the improved quality of multi-frequency measurements with upcoming ground-based and stratospheric…

Astrophysics · Physics 2007-05-23 Yoel Rephaeli

We undertake a reassessment of one of the large angular scale anomalies observed in cosmic microwave background (CMB) temperature signal referred to as Hemispherical Power Asymmetry (HPA). For the present analysis we use \texttt{SEVEM}…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-17 Sanjeev Sanyal , Sanjeet K. Patel , Pavan K. Aluri , Arman Shafieloo
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