Review on the minimally extended varying speed of light model

by Prof. Seokcheon Lee (Sungkyunkwan U)

Wednesday 16 Apr 2025, 16:00 → 18:00 Asia/Seoul

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It is well known that dimensional constants such as ?, c, G, e, and k are human-defined constructs whose values and units depend on the chosen system of measurement. As a result, any time variation in these constants lacks inherent physical significance unless examined within an appropriate framework. While this argument holds in a static or present-day universe, it becomes more nuanced in the context of an expanding universe.

Theoretical and observational evidence strongly supports the notion that the universe is undergoing accelerated expansion. In such a scenario, dimensional quantities?such as the wavelength of light?experience redshift, increasing in size over cosmic time. This raises the possibility that other dimensional constants, including the speed of light, could also vary as the universe expands.

In this seminar, we explore the conditions under which the speed of light might change or remain constant over cosmic time. We also discuss the direct and indirect observational signatures that could distinguish these possibilities. We will specifically discuss the direct observational results of varying speed of light (VSL) from the recent time dilation measurements obtained through the DES SNe program, and also compare these findings with other existing observations, exploring the implications of VSL theory.

 

References: 

3+1 formalism of the minimally extended varying speed of light model 10.1088/1361-6382/ada2d5

The significance of measuring cosmological time dilation in the Dark Energy Survey Supernova Program 10.1016/j.dark.2024.101703

Review on the minimally extended varying speed of light model 10.3390/particles7020019

A viable varying speed of light model in the RW metric 10.1007/s10701-023-00682-1

Constraint on the minimally extended varying speed of light using time dilations in type Ia supernovae 10.1093/mnras/stad2084

Constraining minimally extended varying speed of light by cosmological chronometers 10.1093/mnras/stad1190

The cosmological evolution condition of the Planck constant in the varying speed of light models through adiabatic expansion 10.1016/j.dark.2023.101286

The minimally extended Varying Speed of Light (meVSL) 10.1088/1475-7516/2021/08/054