Related papers: A Time Dependence of QCD
Last year I talked at this meeting about a possible time dependence of the QCD coupling constant $\alpha_s$. This year I shall look into the problem once more, without fully repeating the arguments given last year. Astrophysical indications…
We discuss the fundamemtal constants in the Standard Model of particle physics, in particular possible changes of these constants on the cosmological time scale. The Grand Unification of the observed strong, electromagnetic and weak…
We discuss the fundamental constants of physics in the Standard Model and possible changes of these constants on the cosmological time scale. The Grand Unification of the strong, electromagnetic and weak interactions implies relations…
We briefly review the recent experimental results on possible variations of the fine structure constant $\alpha$ on the cosmological time scale and its position dependence. We outline the theoretical grounds for the assumption that $\alpha$…
Evidence that the fine structure constant, alpha, was different in an early epoch has recently been found in quasar (QSO) absorption spectra. An accurate laboratory measurement of alpha variation could help to distinguish between space and…
Astrophysical indications that the fine structure constant has undergone a small time variation during the cosmological evolution are discussed within the framework of the standard model of the electroweak and strong interactions and of…
In this review we discuss the progress of the past decade in testing for a possible temporal variation of the fine structure constant $\alpha$. Advances in atomic sample preparation, laser spectroscopy and optical frequency measurements led…
A method offering an order of magnitude sensitivity gain is described for using quasar spectra to investigate possible time or space variation in the fine structure constant, alpha. Applying the technique to a sample of 30 absorption…
Astrophysical indications that the fine structure constant has undergone a small time variation during the cosmological evolution are discussed within the framework of the standard model of the electroweak and strong interactions and of…
We describe the results of a search for time variability of the fine structure constant, alpha, using absorption systems in the spectra of distant quasars. Three large optical datasets and two 21cm/mm absorption systems provide four…
We review recent activity searching for variations in the fundamental constants of nature in quasar absorption spectra and in the laboratory. While research in this direction has been ongoing for many decades, the topic has recently been…
Recent experimental data indicates that the fine structure constant alpha may be varying on cosmological time scales. We consider the possibility that such a variation could be induced by a second order phase transition which occurs at late…
We study the space-time evolution of the fine structure constant, $\alpha$, inside evolving spherical overdensities in a lambda-CDM Friedmann universe using the spherical infall model. We show that its value inside virialised regions will…
We review the observational information on the constancy of the fine structure constant alpha. We find that small improvements on the measurement of ^{187}Re lifetime can provide significant progress in exploring the range of variability…
Starting from astrophysical indications that the fine structure constant might undergo a small cosmological time shift, we discuss the implications of such an effect from the point of view of particle physics. Grand unification implies…
There are indications from the study of quasar absorption spectra that the fine structure constant $\alpha$ may have been measurably smaller for redshifts $z>2.$ Analyses of other data ($^{149}$Sm fission rate for the Oklo natural reactor,…
The effect of fractal space time of the quantum particles on the variation of the fine structure constant $\alpha$ has been studied. The variation of fine structure constant has been investigated around De Broglie length $\lambda$ and…
In present paper we evaluate the fine structure constant variation, that should take place as the Universe expands and its curvature is changed adiabatically. Such variation of the fine structure constant is attributed to an energy losses…
Astrophysical observations suggest that the fine structure constant (alpha) may (or may not) be evolving over the cosmological time scale. This raises a much debated question: is alpha variation due to the variation of the speed of light…
A phenomenological model is proposed to explain the recent observed cosmological variation of the fine structure constant as an effect of the quantum vacuum, assuming a flat universe with cosmological constant $\Lambda$ in the cases…