Related papers: Galaxy clusters, type Ia supernovae and the fine s…
In this paper, new bounds on possible variations of the fine structure constant, $\alpha$, for a class of runaway dilaton models are performed. By considering a possible evolution with redshift, $z$, such as…
We propose a new method to probe a possible time evolution of the fine structure constant $\alpha$ from X-ray and Sunyaev-Zeldovich measurements of the gas mass fraction ($f_{gas}$) in galaxy clusters. Taking into account a direct relation…
Galaxy clusters have been used as a cosmic laboratory to verify a possible time variation of fundamental constants. Particularly, it has been shown that the ratio $Y_{SZ}D_{A}^{2}/C_{XZS}Y_X $, which is expected to be constant with…
The angular diameter distances toward galaxy clusters can be determined with measurements of the Sunyaev-Zel'dovich effect and X-ray surface brightness combined with the validity of the distance-duality relation, $D_L(z) (1 +…
In order to probe a possible time variation of the fine-structure constant ($\alpha$), we propose a new method based on Strong Gravitational Lensing and Type Ia Supernovae observations. By considering a class of dilaton runaway models,…
We explore a possible time variation of the fine structure constant ($\alpha \equiv e^2/\hbar c$) using the Sunyaev-Zel'dovich effect measurements of galaxy clusters along with their X-ray observations. Specifically, the ratio of the…
The angular-diameter distance D_A of a galaxy cluster can be measuread by combining its X-ray emission with the cosmic microwave background fluctution due to the Sunyaev-Zeldovich effect. The application of this distance indicator usually…
We propose a new method to probe for variations in the fine structure constant alpha using clusters of galaxies, opening up a window on a new redshift range for such constraints. Hot clusters shine in the X-ray mainly due to bremsstrahlung,…
We have constrained the spatial variation of the fine structure constant using multi-frequency measurements of the thermal Sunyaev-Zeldovich effect of 618 X-ray selected clusters. Although our results are not competitive with the ones from…
We search for a variation of the electromagnetic fine structure constant ($\alpha \equiv e^2/\hbar c$) using a sample of 58 SZ selected clusters in the redshift range ($0.2<z<1.5$) detected by the South Pole Telescope, along with X-ray…
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…
We demonstrate that the recent measurements of the angular diameter distance of 38 cluster of galaxies using Chandra X-ray data and radio observations from the OVRO and BIMA interferometric arrays place new and independent constraints on…
A new method based on large-scale structure observations is proposed to probe a possible time variation of the fine-structure constant ($\alpha$). Our analyses are based on time-delay of Strong Gravitational Lensing and Type Ia Supernovae…
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…
Imaging of the Sunyaev-Zel'dovich (SZ) effect in galaxy clusters combined with cluster plasma x-ray diagnostics can measure the cosmic distance scale to high redshift. Projecting the inverse-Compton scattering and x-ray emission along the…
We propose a new consistent method to test of the distance-duality (DD) relation which related angular diameter distances (DA) to the luminosity distances (DL) in a cosmology-independent way. In order to avoid any bias brought by redshift…
The measurement of angular diameter distance to galaxy clusters, through combined Sunyaev-Zel'dovich (SZ) effect data with X-ray emission observations, is now a well-known probe of cosmology. Using a combination of SZ data and a map of the…
We discuss how the space of possible cosmological parameters is constrained by the angular diameter distance function, D_A(z), as measured using the SZ/X-ray method which combines Sunyaev-Zel'dovich (SZ) effect and X-ray brightness data for…
Combined with X-ray imaging and spectral data, observations of the Sunyaev-Zel'dovich effect (SZE) can be used to determine direct distances to galaxy clusters. These distances are independent of the extragalactic distance ladder and do not…
We performed a systematic and comprehensive estimate of the Hubble constant $H_0$ via the Sunyaev-Zel'dovich temperature decrement and the X-ray measurements for clusters up to the redshift $z=0.541$, with particular attention to its…