Related papers: Ruling the Universe: An Improved Method for Measur…
In this talk I focus on how the modelling of the mass-observable relation and the halo mass function can impact the accuracy and precision of cosmological constraints inferred from galaxy clusters. I present a new analysis of clusters…
The current status of our efforts to trace cosmic structure with 10^6 galaxies (2MASS), 10^3 galaxy clusters (NORAS II cluster survey), and precision measurements for 10^2 galaxy clusters (HIFLUGCS) is given. The latter is illustrated in…
This paper has been withdrawn by the author, due to errors in the figures.
In standard cosmology, the late Universe is assumed to be statistically homogeneous and isotropic. However, a recent study based on galaxy clusters by Migkas et al. (2021, arXiv:2103.13904) found an apparent spatial variation of…
The hypothesis that the late Universe is isotropic and homogeneous is adopted by most cosmological studies. The expansion rate $H_0$ is thought to be spatially constant, while bulk flows are often presumed to be negligible compared to the…
This paper has been withdrawn by author.
We review recent findings that the universe on its largest scales shows hints of the violation of statistical isotropy, in particular alignment with the geometry and direction of motion of the solar system, and missing power at scales…
We examine the prospects for measurement of the Hubble parameter $H_0$ via observation of the secular parallax of other galaxies due to our own motion relative to the cosmic microwave background rest frame. Peculiar velocities make distance…
We present a method to obtain a high-significance detection of relativistic effects on cosmological scales. Measurements of such effects would be instrumental for our understanding of the Universe, as they would provide a further…
Paper has been withdrawn, see comment.
In recent years, significant progress has been made in building new galaxy clusters samples, at low and high redshifts, from wide-area surveys, particularly exploiting the Sunyaev--Zel'dovich (SZ) effect. A large effort is underway to…
A modified version of this paper is under process and with a new title and abstract. Hence, this version of the article is completely withdrawn.
The present paper presents a discussion of classification systems for galaxies, with special emphasis on possible modifications of the Hubble "tuning fork" diagram, and on galaxy types not included in Hubble's original scheme. Hubble's…
The use of galaxy clusters as cosmological probes hinges on our ability to measure their masses accurately and with high precision. Hydrostatic mass is one of the most common methods for estimating the masses of individual galaxy clusters,…
This paper has been withdrawn due to fundamental errors.
Testing possible variations in fundamental constants of nature is a crucial endeavor in observational cosmology. This paper investigates potential cosmological variations in the fine structure constant ($\alpha$) through a non-parametric…
This paper is withdrawn and a corrected, extended and more comprehensive paper is put on as arXiv:0905.2382.
This paper has been withdrawn by the authors due to a crucial error.
The cosmic distance duality relation is a milestone of cosmology involving the luminosity and angular diameter distances. Any departure of the relation points to new physics or systematic errors in the observations, therefore tests of the…
This paper is withdrawn because of an error in Lemma 3.1