Cosmic Acceleration from a Simultaneous Variation of Fundamental Constants

Abstract

We discuss the possibility of a simultaneous cosmic variation of two fundamental entities: the Newtonian gravitational coupling $G$ and the electron mass $m_e$. We show that this variation can account for the late-time cosmic acceleration without invoking a cosmological constant or an explicit dark-energy fluid. We compare the derived $m_e$ variation with laboratory bounds found from Quasar absorption Spectra. Our results indicate that late-time cosmic acceleration could be a manifestation of evolving fundamental couplings, establishing a direct bridge between precision tests of gravity, particle physics and the origin of cosmic acceleration.

Figures (6)

• Figure 1: Top: Plot of the self-interaction potential of the field as a function of redshift. Middle: Plot of the field as a function of redshift. Bottom: Parametric plot of the scalar potential $V(\psi)$ for the general Brans-Dicke framework.
• Figure 2: Variation of $\Delta\mu/\mu$ with $\nu_G$ for the Quintessence Brans-Dicke Framework. Top: $\phi_0 = 0.01$, $n = 1$, positive root. Bottom: $\phi_0 = 0.01$, $n = 1$, positive root.
• Figure 3: Variation of $\Delta\mu/\mu$ with $\phi_0$ for the Quintessence Brans-Dicke framework. Top: $\nu_G = 0.01$, $n = 1$, positive root. Bottom: $\nu_G = 0.01$, $n = 1$, negative root.
• Figure 4: Variation of $\Delta\mu/\mu$ with redshift for both roots of $\psi$ ($\phi_0$=0.01, $w_{\rm eff} = \tfrac{1}{3}$).
• Figure 5: Effective Newton’s constant $G_{\rm eff}(z)/G_0$ as a function of the Higgs vacuum expectation value $\nu(z)$ in the general Brans--Dicke theory. The solid and dashed curves correspond to the positive and negative roots of the scalar field $\psi$, respectively.