Operational indistinguishably of varying speed of light theories

TL;DR

This paper examines two varying speed of light theories and demonstrates that they are essentially re-descriptions of Einstein's special relativity, not new theories.

Contribution

It provides a critical analysis showing that these theories do not extend or modify relativity but are equivalent reformulations.

Findings

Theories are mathematically equivalent to special relativity

They do not introduce new physical principles

Varying speed of light does not lead to new predictions

Abstract

The varying speed of light theories have been recently proposed to solve the standard model problems and anomalies in the ultra high energy cosmic rays. These theories try to formulate a new relativity with no assumptions about the constancy of the light speed. In this regard, we study two theories and want to show that these theories are not the new theories of relativity, but only re-descriptions of Einstein's special relativity.