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In this paper we implement an improved (error sensitive) Richardson-Lucy deconvolution algorithm on the measured angular power spectrum from the WMAP 3 year data to determine the primordial power spectrum assuming different points in the…

Astrophysics · Physics 2008-12-18 Arman Shafieloo , Tarun Souradeep

We present constraints on extensions to the flat $\Lambda$CDM cosmological model by varying the spatial curvature $\Omega_K$, the sum of the neutrino masses $\sum m_\nu$, the dark energy equation of state parameter $w$, and the Hu-Sawicki…

The logotropic model [P.H. Chavanis, Eur. Phys. J. Plus {\bf 130}, 130 (2015)] may be an interesting alternative to the $\Lambda$CDM model. It is able to account for the present accelerating expansion of the universe while solving at the…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-19 Pierre-Henri Chavanis

Spectroscopic observations of the chemical abundances in metal-poor H II regions provide an independent method for estimating the primordial helium abundance. H II regions are described by several physical parameters such as electron…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Erik Aver , Keith A. Olive , Evan D. Skillman

We compile 41 $H(z)$ data from literature and use them to constrain O$\Lambda$CDM and flat $\Lambda$CDM parameters. We show that the available $H(z)$ suffers from uncertainties overestimation and propose a Bayesian method to reduce them. As…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-11 J. F. Jesus , T. M. Gregório , F. Andrade-Oliveira , R. Valentim , C. A. O. Matos

The backreaction term ${\cal Q}_\CD$ and the averaged spatial Ricci scalar $\average{\CR}$ in the spatially averaged inhomogeneous Universe can be used to combine into effective perfect fluid energy density $\varrho_{\rm eff}^{\CD}$ and…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-20 Yan-Hong Yao , Xin-He Meng

We explore the backreaction model based on the template metric proposed in Larena et al. (2008) constraining the matter density parameter $\Omega_m^{D_0}$ and the Dark Energy parameter $w$ with recent data. We provide constraints based on…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-25 Matteo Chiesa , Davide Maino , Elisabetta Majerotto

We consider the determination of $\alpha_s$ from $\tau$ hadronic decays, by investigating the contour-improved (CI) and the fixed-order (FO) renormalization group summations in the frame of a new perturbation expansion of QCD, which…

High Energy Physics - Phenomenology · Physics 2009-11-05 Irinel Caprini , Jan Fischer

Assuming the source of the anomalies observed recently in $b \to s$ data to be new physics, there is a priori no reason to believe that - in the effective field theory language - only one type of operator is responsible for the tensions. We…

High Energy Physics - Phenomenology · Physics 2018-11-30 A. Arbey , T. Hurth , F. Mahmoudi , S. Neshatpour

We report new precise H$(e,e^\prime p)\pi^0$ measurements at the $\Delta(1232)$ resonance at $Q^2= 0.127$ (GeV/c)$^2$ using the MIT/Bates out-of-plane scattering (OOPS) facility. The data reported here are particularly sensitive to the…

Nuclear Experiment · Physics 2009-11-10 N. F. Sparveris , OOPS Collaboration

We implement and investigate a method for measuring departures from scale-invariance, both scale-dependent as well as scale-free, in the primordial power spectrum of density perturbations using cosmic microwave background (CMB) C_l data and…

Astrophysics · Physics 2009-11-11 Samuel Leach

Recently the full O(alpha_S^5 m, alpha_S^5 m log(alpha_S)) correction to the heavy quarkonium 1S energy level has been computed (except the a_3-term in the QCD potential). We point out that the full correction (including the…

High Energy Physics - Phenomenology · Physics 2011-07-19 Y. Kiyo , Y. Sumino

We have applied so-called `optimised' perturbation theory to resolve the renormalisation-scale (mu) ambiguity of exact O(alpha_s^2) QCD calculations of event shape observables in e+e- --> hadrons. We fitted the optimised predictions for 15…

High Energy Physics - Phenomenology · Physics 2009-10-28 P. N. Burrows , H. Masuda , D. Muller , Y. Ohnishi

We use current cosmic microwave background data to constrain cosmological parameters. The results are presented as confidence regions in the ($\Omega$--$H_o$) -- plane for both open and flat geometries, and are based on a $\chi^2$…

Astrophysics · Physics 2007-05-23 J. G. Bartlett , A. Blanchard , M. Le Dour , M. Douspis , D. Barbosa

We update the constraints on the time variation of the fine structure constant $\alpha$ and the electron mass $m_e$, using the latest CMB data, including the 7-yr release of WMAP. We made statistical analyses of the variation of each one of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Susana. J. Landau , Claudia G. Scóccola

We determine the strong coupling constant $\alpha_s(M_Z)$ from the static QCD potential by matching a lattice result and a theoretical calculation. We use a new theoretical framework based on operator product expansion (OPE), where…

High Energy Physics - Phenomenology · Physics 2019-05-24 Hiromasa Takaura , Takashi Kaneko , Yuichiro Kiyo , Yukinari Sumino

We present a Bayesian analysis of cosmological parameter constraints from early- and late-universe observations, focusing on the matter density parameter ($\Omega_m$) and the amplitude of matter fluctuations ($\sigma_8$) within the…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-13 Manjeet Kunwar , Nabin Bhusal , Manil Khatiwada , Niraj Dhital

The quasiparticle effective mass $m^*$ of the three-dimensional uniform electron gas (UEG) is a fundamental Fermi-liquid parameter whose value and density dependence have remained controversial for decades. Using renormalized perturbation…

Strongly Correlated Electrons · Physics 2026-05-05 Pengcheng Hou , Daniel Cerkoney , Zhiyi Li , Tao Wang , Xiansheng Cai , Lei Wang , Gabriel Kotliar , Youjin Deng , Kun Chen

We reconstruct the shape of the primordial power spectrum of curvature perturbations in extended cosmological models, including addition of massive neutrinos, extra relativistic species or varying primordial helium abundance, from the…

Cosmology and Nongalactic Astrophysics · Physics 2012-05-18 Zong-Kuan Guo , Yuan-Zhong Zhang

In this study we investigate potential large-angle anisotropies in the angular distribution of the cosmological parameters $H_0$ (the Hubble constant) and $\Omega_m$ (the matter density) in the flat-$\Lambda$CDM framework, using the…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-08 Rahima Mokeddem , Maria Lopes , Felipe Avila , Armando Bernui , Wiliam S. Hipólito-Ricaldi