Basically, there are two schools of thought. An outdated one, which merges γ into <i>m</i>, and the current one (e.g., the Landau lineage) which leaves <i>m</i> alone. You won&#x27;t find any &quot;relativistic mass&quot; in any decent source published since the famous theoretical minimum ( <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Course_of_Theoretical_Physics" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Course_of_Theoretical_Physics</a> ).<p>There is a very good reason for this approach. In the simplest, most classic way of deriving the special relativity from the first principles, the 4-velocity is introduced <i>before</i> the 4-momentum. I.e., γ and <i>m</i> are coming from different places and are not connected in any ways whatsoever.