Probing the Time Variation of a Fine Structure Constant Using Galaxy Clusters and the Quintessence Model

Abstract

We explore a possible time variation of the fine structure constant (α ≡ e 2/ℏ c) using the Sunyaev–Zel’dovich effect measurements of galaxy clusters along with their X-ray observations. Specifically, the ratio of the integrated Comptonization parameter Y SZ D A 2 and its X-ray counterpart Y X is used as an observable to constrain the bounds on the variation of α. Considering the violation of the cosmic distance duality relation, this ratio depends on the fine structure constant of ∼ α 3. We use the quintessence model to provide the origin of α time variation. In order to give a robust test on α variation, two galaxy cluster samples, the 61 clusters provided by the Planck collaboration and the 58 clusters detected by the South Pole Telescope (SPT), are collected for analysis. Their X-ray observations are given by the XMM-Newton survey. Our results give ζ = − 0.203 − 0.099 + 0.101 for the Planck sample and ζ = − 0.043 − 0.148 + 0.165 for the SPT sample, indicating that α is constant with redshift within 3σ and 1σ for the two samples, respectively.

Consistency test of the fine-structure constant from the whole ionization history

“…[13] obtained α/α EM = 0.9993 ± 0.0025 at 68% C.L.. Comparing other measurements from astrophysics, our constraints are tighter than ∆α/α EM < 10 −2 − 10 −3 from the abundance of light elements during BBN [47], but weaker than constraints of ∆α/α EM ∼ 10 −7 −10 −8 from the 1.8 billion-year-old natural nuclear reactor at the Oklo Uranium Mine in Gabon [48], ∆α/α EM ∼ 10 −5 −10 −6 from the spectral lines of quasars [49][50][51] and so on [16]. However, in the ΛCDM+α rec /α EM + α rei /α EM model, our results show α rec /α EM = 1.001494 +0.002041 −0.002063 and α rei /α EM = 0.8540342 +0.031678 −0.027209 at 68%C.L..…”

“…For reviews of the other measurements, see [15]. Since these measurements may come from different epochs of our universe, it is possible for people to probe a varying fine-structure constant [4,11,16]. Theoretically, the fine-structure constant can be dynamical in a more general framework than the standard model of particle physics.…”

A Hubble constant estimate from galaxy cluster and type Ia SNe observations

“…In the present analysis, we have combined the statistical and systematic errors in quadrature for the angular diameter distance from galaxy clusters. Therefore, the left panel of figure 1 contexts, such as: in cosmological parameter estimates [25,26,79,80], for tests of the cosmic distance duality relation [31,[49][50][51], for tests of fundamental physics [35][36][37], etc.…”

“…[24]), as well as allow to constrain dark energy models [24][25][26][27][28][29][30]. In the last JCAP05(2024)098 years, GCs data have also been used in several other cosmological contexts, such as: for tests of the cosmic distance duality relation [31][32][33][34], for tests of fundamental physics [35][36][37], etc.…”

Varying-$α$ in scalar-tensor theory: Implications in light of the supernova absolute magnitude tension and forecast from GW standard sirens

“…On the other hand, from a more modern perspective, the observational evidence that our Universe is currently in a stage of accelerated expansion lead us to introduce some extra degrees of freedom compared to general rel-ativity (GR), as dark energy models and modified gravity theories, of which also predict cosmic time variation of the fundamental constants. These include scalartensor theories [17][18][19][20], modified Teleparallel gravity [21,22], running vacuum models [23], Bekenstein-Sandvik-Barrow-Magueijo theory [24,25], extra-dimensions [26], dynamical dark energy models [27][28][29][30]. Briefly, in the astronomical context, tight constraints on ∆α/α are obtained from white dwarf observations.…”