Probing the evolution of the gas mass fraction with the Sunyaev-Zeldovich effect

Study of the primary anisotropies of the cosmic microwave background (CMB) can be used to determine the cosmological parameters to a very high precisi on. The power spectrum of the secondary CMB anisotropies due to the thermal Sunyaev-Zeldovich effect (SZE) by clusters of galaxies can then be studied , to constrain more cluster-specific properties (like gas mass). We show th e SZE power spectrum from clusters to be a sensitive probe of any possible evolution (or constancy) of the gas mass fraction. The position of the peak of the SZE power spectrum is a strong discriminatory signature of differen t gas mass fraction evolution models. For example, for a flat universe, the re can be a difference in the l-values (of the peak) of as much as 2500 bet ween a constant gas mass fraction model and an evolutionary one. Moreover, observational determination of the power spectrum, from blank-sky surveys, is devoid of any selection effects that can possibly affect targeted X-ray or radio studies of gas mass fractions in galaxy clusters.