Related papers: Variation of $\alpha$ from a Dark Matter Force
The existing observational data on possible variations of fundamental physical constants (FPC) confirm more or less confidently only a variability of the fine structure constant $\alpha$ in space and time. A model construction method is…
We study constraints on time variation of the fine structure constant alpha from cosmic microwave background (CMB) taking into account simultaneous change in alpha and the electron mass m_e which might be implied in unification theories. We…
In this thesis, we focus on the study of the variation of the electron mass $m_e$, and the fine structure constant $\alpha$, at different cosmic times. We analyze the details of the recombination physics, including helium recombination, in…
Changes in the values of the fundamental constants mu, the proton to electron mass ratio, and alpha, the fine structure constant due to rolling scalar fields have been discussed both in the context of cosmology and in new physics such as…
Review of recent works devoted to the variation of the fundamental constants is presented including atomic clocks, quasar absorption spectra, and Oklo natural nuclear reactor data. Assuming linear variation with time we can compare…
The class of Chaplygin gas models regarded as a candidate of dark energy can be realized by a scalar field, which could drive the variation of the fine structure constant $\alpha$ during the cosmic time. This phenomenon has been observed…
We outline a dynamical dark energy scenario whose signatures may be simultaneously tested by astronomical observations and laboratory experiments. The dark energy is a field with slightly sub-gravitational couplings to matter, a logarithmic…
The bulk of recent cosmological research has focused on the adiabatic cold dark matter model and its simple extensions. Here we present an accurate fitting formula that describes the matter transfer functions of all common variants,…
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…
One of the topical problems of contemporary physics is a possible variability of the fundamental constants. Here we consider possible variability of two dimensionless constants which are most important for calculation of atomic and…
Oscillating ultra-light scalar fields are a natural explanation for the dark matter in our universe, as long as a mechanism, often called a misalignment mechanism, exists to explain the amplitude of the scalar oscillations. If the dark…
It is possible that there may be differences in the fundamental physical parameters from one side of the observed universe to the other. I show that the cosmological constant is likely to be the most sensitive of the physical parameters to…
Models of modified gravity, whereby local tests of gravity are evaded thanks to a screening mechanism of the chameleon or Damour-Polyakov types, lead to a spatial variation of the particle masses and the fine structure constant. This is…
We propose a simple model in which the cosmological dark matter consists of particles whose mass increases with the scale factor of the universe. The particle mass is generated by the expectation value of a scalar field which does not have…
If dark matter is a light scalar field weakly interacting with elementary particles, such a field induces oscillations of the physical constants, which results in time-varying force acting on macroscopic objects. In this paper, we report on…
The evidence for the accelerated expansion of the universe and the time-dependence of the fine-structure constant suggests the existence of at least one scalar field with a mass of order H_0. If such a field exists, then it is generally…
A scale invariant model containing dilaton $\phi$ and dust (as a model of matter) is studied where the shift symmetry $\phi\to\phi +const.$ is spontaneously broken at the classical level due to intrinsic features of the model. The dilaton…
The bound on the time variation of the fine structure constant ($\alpha$) driven by the dynamics of quintessence scalar field which is coupled to electromagnetism is discussed using phenomenological quintessential models constrained by SNIa…
In this note, we investigate the stability of the dark energy model from time crystals proposed in [1]. We emphasize two ingredients, the coupling of the scalar field to gravity, and the fact that these time crystals are on an expanding FRW…
Endeavours of the unification of the four fundamental interactions have resulted in a development of theories having cosmological solutions in which low-energy limits of fundamental physical constants vary with time. The validity of such…