Current and future constraints on extended Bekenstein-type models for a varying fine-structure constant

Abstract

There is a growing interest in astrophysical tests of the stability of dimensionless fundamental couplings, such as the fine-structure constant α, as an optimal probe of new physics. The imminent arrival of the ESPRESSO spectrograph will soon enable significant gains in the precision and accuracy of these tests and widen the range of theoretical models that can be tightly constrained. Here we illustrate this by studying proposed extensions of the Bekenstein-type models for the evolution of α that allow different couplings of the scalar field to both dark matter and dark energy. We use a combination of current astrophysical and local laboratory data (from tests with atomic clocks) to show that these couplings are constrained to parts per million level, with the constraints being dominated by the atomic clocks. We also quantify the expected improvements from ESPRESSO and other future spectrographs, and briefly discuss possible observational strategies, showing that these facilities can improve current constraints by more than an order of magnitude.

Teleparallel Gravity: From Theory to Cosmology

“…10.12. It predominantly consists of an archival astrophysical data set of quasar absorption lines observed at the Keck observatory [779] and with the VLT (V) [658], along with a set of 21 dedicated new measurements (N) [28,753,987,432,680,780,739,99,45], and the constraint from the Oklo (O) natural nuclear reactor at an effective redshift of z = 0.14 [882]. The measurements contained in the N data set were reported from the ESO Ultraviolet and Visual Echelle Spectrograph (UVES) Large Program which was specifically developed for such measurements.…”

Varying fundamental constants and dark energy in the ESPRESSO era

“…Typically they do not directly constrain cosmological parameters, but they may still indirectly help constrain them by breaking degeneracies in the overall parameter space (which will include cosmological and particle physics parameters). The simplest example of this class are the Bekenstein type models 22,23 . In some cases, such as the Dirac-Born-Infeld type models, astrophysical measurements of α may be the only possible observational probe that, given already available constraints, can distinguish these models from ΛCDM 24 .…”

Teaching relativity at the AstroCamp

“…Most editions of the camp also included a computational project, lasting about 20 hours, aiming to provide the students with an introduction to scientific programming and statistics and data analysis in astrophysics. In several cases, the students continued working on these projects after the camp, and contributed to peer-reviewed publications in top academic journals [1][2][3] . At least one more such publication is expected soon.…”