Galaxy clusters, type Ia supernovae and the fine structure constant

R.F.L.HOLANDA; V.C.BUSTI; L.R. COLACO; J.S.ALCANIZ; SUSANA J. LANDAU

JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS

IOP PUBLISHING LTD

Lugar: Londres; Año: 2016 vol. 08 p. 55 - 59

1475-7516

As is well known, measurements of the Sunyaev-Zeldovich effect can becombined with observations of the X-ray surface brightness of galaxy clustersto estimate the angular diameter distance to these structures. In this paper,we show that this technique depends on the fine structure constant, α.Therefore, if α is a time-dependent quantity, e.g., α=α0ϕ(z), where ϕ is a function of redshift, we argue that current data donot provide the real angular diameter distance, DA(z), to the clusterbut instead DdataA(z)=ϕ(z)2DA(z). We use this result toderive constraints on a possible variation of α for a class of dilatonrunaway models considering a sample of 25 measurements of DdataA(z) inredshift range 0.023<z<0.784 and estimates of DA(z) fromcurrent type Ia supernovae observations. We find no significant indication ofvariation of α with the present data.