Gravitational lens time-delay as a probe of a possible time variation of the fine-structure constant

Abstract

A new method based on large scale structure observations is proposed to probe a possible temporal variation of the fine-structure constant ($$\alpha $$ α ). Our analyses are based on time-delay of Strong Gravitational Lensing and Type Ia Supernovae observations. By considering the runaway dilaton scenario, where the cosmological temporal evolution of the fine-structure constant is given by $$\frac{\Delta \alpha }{\alpha } \approx -\gamma \ln {(1+z)}$$ Δ α α ≈ - γ ln ( 1 + z ) , we obtain limits on the physical properties parameter of the model ($$\gamma $$ γ ) at the level $$10^{-2}$$ 10 - 2 ($$1\sigma $$ 1 σ ). Although our limits are less restrictive than those obtained by quasar spectroscopy, the approach presented here provides new bounds on the possibility of $$\frac{\Delta \alpha }{\alpha } \ne 0$$ Δ α α ≠ 0 at a different range of redshifts.

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

“…Most of this kind of work employed the observations of the Sunyaev-Zel'dovich effect (SZ effect, hereafter) combined with observations of the X-ray surface brightness of galaxy clusters, for which the former can be characterized by the integrated Comptonization parameter Y D A SZ 2 and the latter by the Y X parameter (Holanda et al 2017(Holanda et al , 2016a(Holanda et al , 2016bColaço et al 2019;Bora & Desai 2021a. Alternatively, Colaço et al (2021aColaço et al ( , 2021b used combined measurements of strong gravitational lensing systems and Type Ia supernovae to constrain γ. Instead of basing α on runaway models, Galli (2013) assumed that α can linearly vary with redshift, i.e., α/α 0 = A lin (1 + z), and then studied whether α is time-dependent by constraining A lin using the SZ effect and its X-ray counterpart of galaxy clusters.…”

Constraining a possible time-variation of the speed of light along with the fine-structure constant using strong gravitational lensing and Type Ia supernovae observations

“…the runaway dilaton model which assumes the strong coupling limit between matter and the scalar field and is, therefore, able to evade the stringent constraints on violations of the Weak Equivalence Principle (WEP). This model has been used previously to establish constraints of the possible variation in α with galaxy cluster, supernovae type Ia, gravitational lensing, and Sunyaev-Zeldovich data [28][29][30][31][32].…”

“…Besides, constraints on the variation in α in the early universe can be obtained from cosmic microwave background measurements [38][39][40][41][42] and primordial nucleosynthesis [43]. Moreover, other limits can be established from white dwarfs [44,45] and Galaxy clusters [28][29][30][31][32]; among many others.…”