Details of the calculation of back-from-the-future dark energy density
- i.e. in more detailThe Unruh temperature at our future de Sitter cosmic event horizon is, therefore,We are located at r = 0 in this observer-dependent dark energy future universe metric explained by Tamara Davis in her Ph.D. where our r = 0 future light cone intersects it.The static gravity redshift is given in Einstein's GR bywhereTherefore, since the temperature is proportional to the mean photon energy/frequencyTherefore, the Planck temperature at our future horizon (pixelated hologram computer - Seth Lloyd) is cooled down in the form of advanced Wheeler-Feynman-Hawking-Unruh blackbody real photon radiation to virtual photon zero point vibrations whose wavelength is the geometric mean of the quantum gravity Planck scale with cosmological Hubble scale. I say virtual because classically the horizon is an infinite redshift surface. However, redshifted frequency is not the classical zero, but is c/(geometric mean).By the circa 1900 quantum thermodynamics of the blackbody radiation, the energy density scales as the fourth power of the effective temperature, therefore, the dark energy density is (Stefan-Boltzmann)with the factor ~ 10^120 clearly explained.