Related papers: Type Ia Supernovae and Their Cosmological Implicat…
Ongoing searches for supernovae (SNe) at cosmological distances have recently started to provide a link between SN Ia statistics and galaxy evolution. We use recent estimates of the global history of star formation to compute the…
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…
Using 1533 type Ia supernovae (SNe Ia) from the five-year sample of the Dark Energy Survey (DES), we investigate the relationship between the projected galactocentric separation of the SNe and their host galaxies and their light curves and…
Type Ia Supernova(SN Ia) are a powerful, albeit not completely understood, tool for cosmology. Gaps in our understanding of their progenitors and detailed physics can lead to systematic errors in the cosmological distances they measure. We…
We used the GMBCG galaxy cluster catalogue and SDSS-II supernovae data with redshifts measured by the BOSS project to identify 48 SNe Ia residing in rich galaxy clusters and compare their properties with 1015 SNe Ia in the field. Their…
We present an improved measurement of the Hubble constant (H_0) using the 'inverse distance ladder' method, which adds the information from 207 Type Ia supernovae (SNe Ia) from the Dark Energy Survey (DES) at redshift 0.018 < z < 0.85 to…
After correcting for their light-curve shape and color, Type Ia supernovae (SNe Ia) are precise cosmological distance indicators. However, there remains a non-zero intrinsic scatter in the differences between measured distance and that…
The Hubble's constant is usually surmised to be a constant; but the experiments show a large spread and conflicting estimates. According to the plasma-redshift theory, the Hubble's constant varies with the plasma densities along the line of…
The light curve of a distant Type Ia supernova acts like a clock that can be used to test the expansion of the Universe. SN~1995K, at a spectroscopic redshift of $z = 0.479$, provides one of the first meaningful data sets for this test. We…
Type Ia supernovae (SNe Ia) are explosions of white dwarf stars that facilitate exquisite measurements of cosmological expansion history, but improvements in accuracy and precision are hindered by observational biases. Of particular concern…
We explore the systematic uncertainties of using Type Ia supernovae (SNe Ia) as cosmological probes, using the Supernova Legacy Survey Three Year data (SNLS3). We focus on studying the possible evolution of the stretch-luminosity parameter…
The distribution of high redshift Type Ia supernovae (SNe Ia) with respect to projected distance from the center of the host galaxy is studied and compared to the distribution of local SNe. The distribution of high-z SNe Ia is found to be…
The High-z Supernova Search Team has discovered and observed 8 new supernovae in the redshift interval z=0.3-1.2. These independent observations, confirm the result of Riess et al. (1998a) and Perlmutter et al. (1999) that supernova…
We apply two methods, namely the Gaussian processes and the non-parametric smoothing procedure, to reconstruct the Hubble parameter $H(z)$ as a function of redshift from 15 measurements of the expansion rate obtained from age estimates of…
We study intermediate--z SNe Ia using the empirical physical diagrams which enable to learn about those SNe explosions. This information can be very useful to reduce systematic uncertainties of the Hubble diagram of SNe Ia up to high z. The…
We use the HST ACS imaging of the two GOODS fields during Cycles 11, 12, and 13 to derive the Type Ia supernova rate in four redshift intervals in the range 0.2<z<1.8. Compared to our previous results based on Cycle 11 observations only, we…
There is a persistent tension of about $5\sigma-6\sigma$ between the value of the Hubble constant, as derived from the local distance ladder vs. the cosmic microwave background, signaling either unaccounted for systematics in the…
Recent studies indicate that Type Ia supernovae (SNe Ia) consist of two groups - a "prompt" component whose rates are proportional to the host galaxy star formation rate, whose members have broader lightcurves and are intrinsically more…
Supernovae Ia (SNe Ia) light curves have been used to prove the universe is expanding. As standard candles, SNe Ia appear to indicate the rate of expansion has increased in the past and is now decreasing. This independent evaluation of SNe…
Constraints on dark energy from current observational data are sensitive to how distances are measured from Type Ia supernova (SN Ia) data. We find that flux-averaging of SNe Ia can be used to test the presence of unknown systematic…