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In this paper, the cosmological parameters are determined by applying six cosmological models to fit the magnitude-redshift relation of the Pantheon Sample consisting of 1048 Type Ia supernovae (SNe Ia) in the range of $0.01 < z < 2.26$.…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-18 Peifeng Peng , Nigel Metcalfe

We present constraints on the amplitude of matter fluctuations from the clustering of galaxies and their cross-correlation with the gravitational lensing convergence of the cosmic microwave background (CMB), focusing on low redshifts…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-13 Andrea Rubiola , Matteo Zennaro , Carlos García-García , David Alonso

There are two redshifts in cosmology: $z_{obs}$, the observed redshift computed via spectral lines, and the model redshift, $z$, defined by the effective FLRW scale factor. In general these do not coincide. We place observational…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-06 Bruce A. Bassett , Yabebal Fantaye , Renée Hložek , Cristiano Sabiu , Mat Smith

If the assumption that physical space has a trivial topology is dropped, then the Universe may be described by a multiply connected Friedmann-Lema\^{\i}tre model on a sub-horizon scale. Specific candidates for the multiply connected space…

Astrophysics · Physics 2011-05-23 Boudewijn F. Roukema , Jean-Pierre Luminet

We present limits on the parameters of the o$\Lambda$CDM, $w_0$CDM, and $w_0 w_a$CDM models obtained from the joint analysis of the full-shape, baryon acoustic oscillations (BAO), big bang nucleosynthesis (BBN) and supernovae data. Our…

Cosmology and Nongalactic Astrophysics · Physics 2021-02-16 Anton Chudaykin , Konstantin Dolgikh , Mikhail M. Ivanov

We use the Gurvits, Kellermann, & Frey compact radio source angular size versus redshift data to place constraints on cosmological model parameters in models with and without a constant or time-variable cosmological constant. The resulting…

Astrophysics · Physics 2009-11-07 Gang Chen , Bharat Ratra

Cosmological constraints are usually derived under the assumption of a $6$ parameters $\Lambda$-CDM theoretical framework or simple one-parameter extensions. In this paper we present, for the first time, cosmological constraints in a…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-30 Eleonora Di Valentino , Alessandro Melchiorri , Joseph Silk

We present cosmological constraints for the flat $\Lambda$CDM model, including the sum of neutrino masses, by performing a multi-probe analysis of a total of 13 tomographic auto- and cross-angular power spectra. This is achieved by…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-11 Raphael Sgier , Christiane Lorenz , Alexandre Refregier , Janis Fluri , Dominik Zürcher , Federica Tarsitano

In this paper we obtain constraints on the cosmological density parameters, \Omega_m and \Omega_b, by comparing the preliminary measurement of the QSO power spectrum from the two degree field QSO redshift survey with results from an…

Astrophysics · Physics 2009-11-07 Kazuhiro Yamamoto

The periodic solution of the Friedmann equation in conformal time, implies that only cosmological perturbations exhibiting corresponding symmetries are physically permissible, leading to a discrete spectrum of allowed wave vectors.…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-15 Wei-Ning Deng , Will Handley

We explore the cosmological consequences of a modified cosmology inspired by string T-duality. We incorporate the zero-point length correction, $l_0$, into the gravitational potential and derive the modified Friedmann equations via…

General Relativity and Quantum Cosmology · Physics 2026-05-29 G. G. Luciano , A. Paliathanasis , A. Sheykhi

The standard model of cosmology, {\Lambda}CDM, is the simplest model that matches the current observations, but it relies on two hypothetical components, to wit, dark matter and dark energy. Future galaxy surveys and cosmic microwave…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-13 Cyrille Doux , Mariana Penna-Lima , Sandro D. P. Vitenti , Julien Tréguer , Eric Aubourg , Ken Ganga

We make use of the Gaia-Unwise quasar catalogue, Quaia, to constrain the growth history out to high redshifts from the clustering of quasars and their cross-correlation with maps of the Cosmic Microwave Background (CMB) lensing convergence.…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-09 G. Piccirilli , G. Fabbian , D. Alonso , K. Storey-Fisher , J. Carron , A. Lewis , C. García-García

Recent astronomical observations of SNIa, CMB, as well as BAO in the Sloan Digital Sky Survey, suggest that the current Universe has entered a stage of an accelerated expansion with the transition redshift at $z \simeq 0.5$. While the…

Astrophysics · Physics 2010-11-11 Aleksandra Kurek , Marek Szydlowski

We present a cosmic shear analysis of the 100 square degree weak lensing survey, combining data from the CFHTLS-Wide, RCS, VIRMOS-DESCART and GaBoDS surveys. Spanning ~100 square degrees, with a median source redshift z~0.78, this combined…

We derive several, detailed relationships in terms of the Friedmann, Robertson, Walker (FRW) generalization which describe the Universe during both the radiation and matter dominated epochs. We explicitly provide for the influence of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Ahmet M. Öztaş , Michael L. Smith

We use updated Type Ia Pantheon+ supernova, baryon acoustic oscillation, and Hubble parameter (now also accounting for correlations) data, as well as new reverberation-measured C IV quasar data, and quasar angular size, H II starburst…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-19 Shulei Cao , Bharat Ratra

We investigate what current cosmological data tells us about the cosmological expansion rate in a model independent way. Specifically, we study if the expansion was decelerating at high redshifts and is accelerating now, without referring…

Astrophysics · Physics 2009-11-13 Edvard Mortsell , Chris Clarkson

Currently, the $\Lambda$ Cold Dark Matter model, which relies on the existence of cold dark matter and a cosmological constant $\Lambda$, best describes the Universe. However, we lack information in the high-redshift ($z$) region between…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-28 Maria Giovanna Dainotti , Giada Bargiacchi , Aleksander Łukasz Lenart , Shigehiro Nagataki , Salvatore Capozziello