Related papers: A fitting function for the SNAP data

In order to deal with a large cosmological constant a relaxation mechanism based on modified gravity has been proposed recently. By virtue of this mechanism the effect of the vacuum energy density of a given quantum field/string theory (no…

We present a novel technique for fitting restframe I-band light curves on a data set of 42 Type Ia supernovae (SNe Ia). Using the result of the fit, we construct a Hubble diagram with 26 SNe from the subset at 0.01< z<0.1. Adding two SNe at…

Analysed in the framework of homogeneous FLRW models, the magnitude-redshift data from high redshift supernovae yield, as a primary result, a strictly positive cosmological constant. Another reading of the currently published measurements…

We study the effect of a phenomenological parameterized quintessence model on low, intermediate and high redshift observations. At low and intermediate redshifts, we use the Gold sample of supernova Type Ia (SNIa) data and recently observed…

We examine the utility of very high redshift Type Ia supernovae for cosmology and systematic uncertainty control. Next generation space surveys such as the Supernova/Acceleration Probe (SNAP) will obtain thousands of supernovae at z>1.7,…

Distance--redshift relations are given in terms of associated Legendre functions for partially filled beam observations inspatially flat Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmologies. These models are dynamically pressure-free,…

Understanding the acceleration of the universe and its cause is one of the key problems in physics and cosmology today, and is best studied using a variety of mutually complementary approaches. Daly and Djorgovski (2003, 2004) proposed a…

Some functions entering cosmological analysis, such as the dark energy equation of state or systematic uncertainties, are unknown functions of redshift. To include them without assuming a particular form we derive an efficient method for…

Recently collected SNIa data have been used to address the problem of measuring the cosmological parameters of the universe. Analysed in the framework of homogeneous models, they have yielded, as a primary result, a strictly positive…

The critical issue in cosmology today lies in determining if the cosmological constant is the underlying ingredient of dark energy. Our profound lack of understanding of the physics of dark energy places severe constrains on our ability to…

The Supernova/Acceleration Probe (SNAP) is a proposed space-borne observatory that will survey the sky with a wide-field optical/near-infrared (NIR) imager. The images produced by SNAP will have an unprecedented combination of depth,…

With data from Pantheon, we have at our disposal a sample of more than a thousand supernovae Ia covering a wide range of redshifts with good precision. Here we make fits to the corresponding Hubble--Lema\^itre diagram with various…

Supernova cosmology surveys are traditionally time consuming, especially for the critical spectroscopic data. However, a single spectrum at maximum light may provide accurate distance estimation if recent developments hold. This could open…

When using distance measurements to probe spatial curvature, the geometric degeneracy between curvature and dark energy in the distance-redshift relation typically requires either making strong assumptions about the dark energy evolution or…

We compile radio supernova remnant (SNR) samples from the literature for 19 nearby galaxies ranging from the SMC to Arp 220, and use this data to constrain the SNR luminosity function (LF) at 20 cm. We find that radio SNR populations are…

The analysis of Type Ia supernova data over the past decade has been a notable success story in cosmology. These standard candles offer us an unparalleled opportunity of studying the cosmological expansion out to a redshift of ~1.5. The…

We consider a very simple toy model for a spatially varying `cosmological constant', where we are inside a spherical bubble (with a given set of cosmological parameters) that is surrounded by a larger region where these parameters are…

The current observations are usually explained by an accelerating expansion of the present universe. However, with the present quality of the supernovae Ia data, the allowed parameter space is wide enough to accommodate the decelerating…

Supernova Ia redshifts are fitted with a simple $5D$ model: the galaxies are assumed to be enclosed in a giant $S^3$-spherical shell of significant thickness, which expands (ultra)relativisticaly in Minkowski (1+4)$D$-space. This model, as…

Observations of distant type Ia supernovae (SNe Ia), used as standard candles, support the notion that the Cosmos is filled with a mysterious form of energy, the dark energy. The constraints on cosmological parameters derived from data of…