Skip to main content# Age of globular clusters and time-variation of fundamental constants

Presentation #209.05 in the session Cosmology I.

Published onJun 29, 2022

Age of globular clusters and time-variation of fundamental constants

Equations governing the evolution of a star involve multiple fundamental constants. Thus, the time it spends as a main-sequence star can be expected to depend on whether or not such constants vary over the time scale of stellar evolution. When the star belongs to a globular cluster, then the star’s age cannot exceed that of the globular cluster, and the latter cannot exceed the age of the Universe. This fact can be used to constrain or verify the variation of the constants, e.g., the speed of light *c*, the gravitational constant *G*, the Planck constant *h*, and the Boltzmann constant *k*. We have estimated the age of the main-sequence star analytically from the time it takes to synthesize all its hydrogen into helium under fixed and varying constants scenarios. When we permitted the concurrent variation of the four constants and differentiated between the cosmological energy and local energy conservation laws, we could show that the variation of the constants established in our earlier studies, i.e., *G ̇/G*=3*c ̇/c=3h ̇/h=1.5k ̇/k=*3.90(±0.04)×10^{-10} yr^{-1} at the current cosmic time, is corroborated with the present work.