From Nikolay Umov E=kmc2 via Albert Einstein’s E=γmc2 to the Dark Energy Density of the Cosmos E=(21/22)mc2

The paper starts from the remarkable classical equation of the great nineteenth century Russian physicist Nikolay Umov E=kmc2 where 1/2≤k≤1, m is the mass, c is the speed of light and E is the equivalent energy of m. After a short but deep discussion of the derivation of Umov we move to Einstein’s formula E=γmc2 where γ is the Lorentz factor of special relativity and point out the interesting difference and similarity between Umov’s k and Lorentz-Einstein γ. This is particularly considered in depth for the special case which leads to the famous equation E=mc2 that is interpreted here to be the maximal cosmic energy density possible. Subsequently we discuss the dissection of E=mc2 into two components, namely the cosmic dark energy density E(D)=(21/22)MC2 and the ordinary energy density E(O)=MC2/22 where E(D)+E(O)=MC2. Finally we move from this to the three-part dissection where we show that E is simply the sum of pure dark energy E(PD) plus dark matter energy E(DM) as well as ordinary energy E(O).