Searching for a secular variation of the gravitational constant using strong gravitational fields.

Searching for variations in dimensionless physical constants presents a meaningful characteristic in experimental and observational studies. One of the most valuable explorations of these variations could depend on the evolution of white dwarf stars. By analyzing the spectrum of the white dwarf star G191-B2B, we derive a robust limit on the cosmological variation of the gravitational constant: G ˙ / G = (0.238 ± 2.959) × 10 - 15 yr - 1 . This limit proposes a potential test of the framework of modern unification theories. [ABSTRACT FROM AUTHOR]