Related papers: Probing variation of the fine-structure constant i…
Strongly-lensed supernovae are rare and valuable probes of cosmology and astrophysics. Upcoming wide-field time-domain surveys, such as the Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST), are expected to discover an…
The energy density of a scalar field $\phi$ with potential $V(\phi) \propto \phi^{-\alpha}$, $\alpha > 0$, behaves like a time-variable cosmological constant that could contribute significantly to the present energy density. Predictions of…
A theory of special inconstancy, in which some fundamental physical constants such as the fine-structure and gravitational constants may vary, is proposed in pregeometry. In the special theory of inconstancy, the \alpha-G relation of…
Model-independent constraints on the spatial curvature are not only closely related to important problems such as the evolution of the Universe and properties of dark energy, but also provide a test of the validity of the fundamental…
We reconsider several current bounds on the variation of the fine-structure constant in models where all gauge and Yukawa couplings vary in an interdependent manner, as would be expected in unified theories. In particular, we re-examine the…
There is a growing interest in astrophysical tests of the stability of dimensionless fundamental couplings, such as the fine-structure constant $\alpha$, as an optimal probe of new physics. The imminent arrival of the ESPRESSO spectrograph…
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…
We consider the possibility of the coupling constants of the $SU(3)\times SU(2)\times U(1)$ gauge interactions at the time of big bang nucleosynthesis having taken different values from what we measure at present, and investigate the…
$f(R)$ gravity, capable of driving the late-time acceleration of the universe, is emerging as a promising alternative to dark energy. Various $f(R)$ gravity models have been intensively tested against probes of the expansion history,…
There has been some evidence that the fine structure "constant" $\alpha$ may vary with time. We point out that this variation can be described by a scalar field in some supergravity theory in our toy model, for instance, the N=8 extended…
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…
We use Bloch oscillations to transfer coherently many photon momenta to atoms. Then we can measure accurately the recoil velocity $\hbar k/m$ and deduce the fine structure constant $\alpha$. The velocity variation due to Bloch oscillations…
We use a combination of simulated cosmological probes and astrophysical tests of the stability of the fine-structure constant $\alpha$, as expected from the forthcoming European Extremely Large Telescope (E-ELT), to constrain the class of…
Searching for space-time variations of the constants of Nature is a promising way to search for new physics beyond General Relativity and the standard model motivated by unification theories and models of dark matter and dark energy. We…
We present an empirical model of Type Ia supernovae spectro-photometric evolution with time. The model is built using a large data set including light-curves and spectra of both nearby and distant supernovae, the latter being observed by…
We analyse the constraints obtained from new atomic clock data on the possible time variation of the fine structure `constant' and the electron-proton mass ratio and show how they are strengthened when the seasonal variation of Sun's…
The Generalized Cosmological Time (GCT) framework interprets the observed time dilation in Type Ia supernovae (SNe Ia) as a manifestation of a generalized lapse function in the background metric, favoring a parameter value b \approx 0.04.…
The observation of strongly lensed Type Ia supernovae enables both the luminosity and angular diameter distance to a source to be measured simultaneously using a single observation. This feature can be used to measure the distance duality…
We present a new framework to study the time variation of fundamental constants in a model-independent way. Model independence implies more free parameters than assumed in previous studies. Using data from atomic clocks based on $^{87}$Sr,…
The gravitational lensing magnification or demagnification due to large-scale structures induces a scatter in peak magnitudes of high redshift type Ia supernovae (SNe Ia). The amplitude of the lensing dispersion strongly depends on that of…