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Type Ia supernovae have light curves that have widths and magnitudes that can be used for testing cosmologies and they provide one of the few direct measurements of time dilation. It is shown that the standard analysis that calibrates the…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-25 David F. Crawford

This presentation reports on first evidence for a low-mass-density/positive-cosmological-constant universe that will expand forever, based on observations of a set of 40 high-redshift supernovae. The experimental strategy, data sets, and…

By using the Sloan Digital Sky Survey (SDSS) first year type Ia supernova (SN Ia) compilation, we compare two different approaches (traditional \chi^2 and complete likelihood) to determine parameter constraints when the magnitude dispersion…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 B. L. Lago , M. O. Calvão , S. E. Jorás , R. R. R. Reis , I. Waga , R. Giostri

We investigate the potential of using a sample of very high-redshift ($2\lesssim z \lesssim6$) (VHZ) Type Ia supernovae (SNe~Ia) attainable by the James Webb Space Telescope (JWST) on constraining cosmological parameters. At such high…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-21 Jia Lu , Lifan Wang , Xingzhuo Chen , David Rubin , Saul Perlmutter , Dietrich Baade , Jeremy Mould , Jozsef Vinko , Eniko Regos , Anton M. Koekemoer

In the context of the dispersion relation $c = \lambda \nu$ and considering an expanding universe where the observed wavelength today is redshifted from the emitted wavelength by $\lambda_{0} = \lambda_{\text{emit}} (1+z)$, to keep $c$…

General Physics · Physics 2024-10-28 Seokcheon Lee

This paper aims to put constraints on the transition redshift $z_t$, which determines the onset of cosmic acceleration, in cosmological-model independent frameworks. In order to perform our analyses, we consider a flat universe and {assume}…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-31 J. F. Jesus , R. F. L. Holanda , S. H. Pereira

The existence of 'peculiar' velocities due to the formation of cosmic structure marks a point of discord between the real Universe and the usually assumed Friedmann-Lema\'{i}tre-Robertson-Walker metric which accomodates only the smooth…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-09 Roya Mohayaee , Mohamed Rameez , Subir Sarkar

We investigate the potential of a future supernovae data set, as might be obtained by the proposed SNAP satellite, to discriminate between two possible explanations for the observed dimming of the high redshift type IA supernovae, namely…

Astrophysics · Physics 2009-11-06 S. C. C. Ng , D. L. Wiltshire

The cosmological concordance model is consistent with all available observational data, including the apparent distance and redshift relationship for distant supernovae, but it is curious how the Milne cosmological model is able to make…

General Physics · Physics 2007-05-23 Alasdair Macleod

We present observations of 10 type Ia supernovae (SNe Ia) between 0.16 < z < 0.62. With previous data from our High-Z Supernova Search Team, this expanded set of 16 high-redshift supernovae and 34 nearby supernovae are used to place…

With a basic varying space-time cutoff $\tilde\ell$, we study a regularized and quantized Einstein-Cartan gravitational field theory and its domains of ultraviolet-unstable fixed point $g_{\rm ir}\gtrsim 0$ and ultraviolet-stable fixed…

General Relativity and Quantum Cosmology · Physics 2015-09-09 She-Sheng Xue

We study the dependence of the peak luminosity of Type Ia supernovae on the fine structure constant $\alpha$. We find that decreasing (increasing) $\alpha$ enhances (reduces) the luminosity. Future experiments like SNAP could determine the…

Astrophysics · Physics 2009-11-10 Takeshi Chiba , Kazunori Kohri

Analysis of type 1a supernovae observations out to a redshift of $z$=1.6 shows that there is good agreement between the light-curve widths and $(1+z)$ which is usually interpreted as a strong support for time dilation due to an expanding…

General Physics · Physics 2010-09-12 David F. Crawford

We consider nonlinear redshift-dependent equation of state parameters as dark energy models in a spatially flat Friedmann-Lema\^itre-Robertson-Walker universe. To depict the expansion history of the universe in such cosmological scenarios,…

General Relativity and Quantum Cosmology · Physics 2018-02-06 Weiqiang Yang , Supriya Pan , Andronikos Paliathanasis

The Foundation Supernova Survey aims to provide a large, high-fidelity, homogeneous, and precisely-calibrated low-redshift Type Ia supernova (SN Ia) sample for cosmology. The calibration of the current low-redshift SN sample is the largest…

The cosmological constant problem has become one of the most important ones in modern cosmology. In this paper, we try to construct a model that can avoid the cosmological constant problem and have the potential to explain the apparent…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-26 Shuxun Tian

With the non-metricity scalar $Q$ as the functional argument, several $f(Q)$ gravity models are found to be proposed which are perfectly able to mimic the late-time accelerated expansion as pointed out by the type Ia supernovae…

General Relativity and Quantum Cosmology · Physics 2026-02-03 Subhajit Pal , Atanu Mukherjee , Ritabrata Biswas , Farook Rahaman

We present photometric and spectroscopic observations of 23 high redshift supernovae spanning a range of z=0.34-1.03, 9 of which are unambiguously classified as Type Ia. These supernovae were discovered during the IfA Deep Survey, which…

It is generally argued that the present cosmological observations support the accelerating models of the universe, as driven by the cosmological constant or `dark energy'. We argue here that an alternative model of the universe is possible…

Astrophysics · Physics 2009-11-07 J. V. Narlikar , R. G. Vishwakarma , G. Burbidge

Cosmic opacity may vary spatially due to the inhomogeneous distribution of dust, its grain properties, and the efficiency of photon attenuation. In this work, we present a model independent method to investigate the variation of cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-29 Savita Gahlaut , Meetu Luthra