Related papers: A Time Variation of the QCD Coupling Constant
Cosmological variation of the fine structure constant $\alpha$ due to the evolution of a spatially homogeneous ultra-light scalar field ($m \sim H_0$) during the matter and $\Lambda$ dominated eras is analyzed. Agreement of $\Delta…
By allowing for non zero vacuum expectation values for some of the fields that appear in the Hamiltonian constraint of canonical general relativity a time variable, with usual properties, can be identified; the constraint plays the role of…
The possibility is examined that the masses of the light quarks $u$ and $d$ have varied over the course of the universe's evolution. Such a variation would have an effect on axion cosmology, and can be the basis of a solution of the…
Determination of the fine structure constant alpha and search for its possible variation are considered. We focus on a role of the fine structure constant in modern physics and discuss precision tests of quantum electrodynamics. Different…
A spacetime interval connecting two neighbouring points can be measured in different unit systems. For instance, it can be measured in atomic unit defined in terms of fundamental constants existing in quantum theories. It is also possible…
We study a theory in which the electromagnetic field is disformally coupled to a scalar field, in addition to a usual non-minimal electromagnetic coupling. We show that disformal couplings modify the expression for the fine-structure…
We analyze different data of the variation of the fine structure constant obtained with different methods to check their consistency.We test consistency using the modified Student test and confidence intervals. We split the data sets in…
Theoretical background of our proposed relation between the accelerating universe and the time-variability of the fine-structure constant is discussed, based on the scalar-tensor theory, with emphases on the intuitive aspects of underlying…
Contemporary multidimensional cosmological theories predict different variations of fundamental physical constants in course of the cosmological evolution. On the basis of the QSO spectra analysis, we show that the fine-structure constant…
By employing Dirac LNH, and a further generalization by Berman (GLNH), we estimate how should vary the total number of nucleons, the energy density, Newton Gravitational constant, the cosmological constant, the magnetic permeability and…
We argue that the discrepancy between the Planck mass scale and the observed value of the cosmological constant can be largely attenuated if those quantities are understood as a result of effective, and thus scale-dependent, couplings. We…
We will look for an implementation of new symmetries in the space-time structure and their cosmological implications. This search will allow us to find a unified vision for electrodynamics and gravitation. We will attempt to develop a…
We start with a brief account of the latest analysis of the Oklo phenomenon providing the still most stringent constraint on time-variability of the fine- structure constant $\alpha$. Comparing this with the recent result from the…
An accelerated universe should naturally have a vacuum energy density determined by its dynamical curvature. The cosmological constant is most likely a temporary description of a dynamical variable that has been drastically evolving from…
Instabilities of equilibrium quantum mechanics are common and well-understood. They are manifested for example in phase transitions, where a quantum system becomes so sensitive to perturbations that a symmetry can be spontaneously broken.…
We study atomic systems that are in the frequency range of optical atomic clocks and have enhanced sensitivity to potential time-variation of the fine structure constant, alpha. The high sensitivity is due to coherent contributions from…
Effective coupling constant in quantum electrodynamics is investigated. A pole appears in the effective coupling constant for the space-like momentum if it is calculated by perturbation. The pole can be eliminated by the analytic…
We discuss the cosmological evolution of cosmic strings with time-dependent tension. We show that, in the case that the tension changes as a power of time, the cosmic string network obeys the scaling solution: the characteristic scale of…
We calculate the dependence of the nuclear magnetic moments on the quark masses including the spin-spin interaction effects and obtain limits on the variation of the fine structure constant $\alpha$ and $(m_q/\Lambda_{QCD})$ using recent…
The current observational and experimental bounds on the time variation of the constants of nature (the fine structure constant $\alpha$, the gravitational constant $G$ and the proton-electron mass ratio $\mu=m_p/m_e$) are reviewed.