Related papers: Does the Fine Structure Constant Really Vary in Ti…
Webb et al. presented preliminary evidence for a time-varying fine-structure constant. We show Teller's formula for this variation to be ruled out within the Einstein-de Sitter universe, however, it is compatible with cosmologies which…
We consider a long range scalar force that mainly couples to dark matter and unstable Standard Model states, like the muon, with tiny strength. Probing this type of force would present a challenge to observations. We point out that the…
Verification of theoretical predictions of an oscillating behavior of the fine-structure constant alpha with cosmic time requires high precision Delta alpha/alpha measurements at individual redshifts, while in earlier studies the mean Delta…
We introduce a model which allows the fine structure constant (alpha) to vary throughout space and time due to a coupling to a scalar field with a non-canonical kinetic structure. This provided a new extension of the…
If the recent observations suggesting a time variation of the fine structure constant are correct, they imply the existence of an ultra light scalar particle. This particle inevitably couples to nucleons through the \alpha-dependence of…
Sensitivity of the frequencies of twenty two atomic transitions to the variation of the fine structure constant $\alpha$ is calculated. The findings are to be used in search for possible variation of $\alpha$ across our Galaxy using high…
Many modern theories predict that the fundamental constants depend on time, position, or the local density of matter. We develop a spectroscopic method for pulsed beams of cold molecules, and use it to measure the frequencies of microwave…
Theories unifying gravity and other interactions suggest the possibility of spatial and temporal variation of physical ``constants''. Accuracy achieved for the atomic optical frequency standards (optical clocks) approaches the level when…
We extend our recent work on the effects of a time-varying fine-structure constant $\alpha$ in the cosmic microwave background, by providing a thorough analysis of the degeneracies between $\alpha$ and the other cosmological parameters, and…
Theories unifying gravity with other interactions suggest spatial and temporal variation of fundamental ``constants'' in the Universe. A change in the fine structure constant, alpha, could be detected via shifts in the frequencies of atomic…
Some attempts of easing the critical Hubble tension present in modern cosmology have resorted to using variations of fundamental constants, such as the fine-structure constant, at the time of recombination. In this article we demonstrate…
Sensitivity to temporal variation of the fundamental constants may be strongly enhanced in transitions between narrow close levels of different nature. This enhancement may be realized in a large number of molecules due to cancelation…
We critically assess recent claims suggesting that upper limits on the time variation of the fine-structure constant tightly constrain the coupling of a dark energy scalar field to the electromagnetic sector, and, indirectly, the violation…
We discuss present and future cosmological constraints on variations of the fine structure constant $\alpha$ induced by an early dark energy component having the simplest allowed (linear) coupling to electromagnetism. We find that current…
Dynamical models of dark energy can imply that the fine structure constant $\alpha$ varies over cosmological time scales. Data on shifts in resonance energies $E_r$ from the Oklo natural fission reactor have been used to place restrictive…
Spacetime variations of physical constants can be associated with the existence of Higgs-like scalar field(s) that couple non-universally to the baryonic matter. Recent results of astronomical spectral measurements of the fractional changes…
We consider the problem of the evolution of the fine structure coefficient alpha under the assumption that the scalar field coupling to the Maxwell term satisfies the condition mt>>1 for coherent dark matter oscillations. In this case we…
Recent detections of high-redshift absorption by both atomic hydrogen and molecular gas in the radio spectra of quasars have provided a powerful tool to measure possible temporal and spatial variations of physical `constants' in the…
We study ultranarrow $5s_{1/2}$ - $4f_{5/2}$ transitions in Nd$^{13+}$ and Sm$^{15+}$ and demonstrate that they lie in the optical region. The transitions are insensitive to external perturbations. At the same time they are sensitive to the…
A possibility for fundamental constants to vary in time is suggested by theories unifying gravity with other interactions. In this article we examine proposals to use optical transitions of Sr, Dy, YbII and YbIII for the search of the time…