Abstract: The Dark Energy (DE) is ubiquitously widespread not just within intergalactic but also intra-atomic spaces. As known, the space between the nucleus and the orbiting electrons is swarming with photons (Ps). DE appears to be associated with an apparently empty space. Just the omnipresent, un-eliminable quantum vacuum energy is the key element to help us discover the identikit of the Dark Energy Particles, for us represented in the last analysis by invisible Ps DE is nothing more than the sum of the common photonic energy of a considerable number of Ps, often inexorably more and more compressed by the Gravity Interaction, until the radiation cannot be further compressed. These considerations are elegantly illustrated by the equation: PV 4/3 = C, where according to Feynman V is the Volume and P the Pressure of the photonic gas, so we know the Compressibility (C) of the radiation!. DE is conveyed by Ps, also of different energies, engaged in various tasks and operating spaces, whose common denominator is represented by the impossibility of being compressed beyond a determined limit. In short, DE is represented by a Photonic Counter-Pressure, or negative pressure, that is expansive, repulsive, anti-gravity, exerted by Psno further thickened and compressible.
Keywords: Energy Particles, Photons