"Cosmological Constant and Archimedes' Principle"

We investigate the origin of the cosmological constant, which plays a crucial role in the accelerated expansion of the Universe. By analyzing the energy-momentum tensor form factors of hadrons, we find that the QCD trace anomaly balances the pressures from quarks and gluons, thus playing a key role in hadron confinement. The source of this anomaly is traced to the gluon condensate of the vacuum. A similar phenomenon occurs in type II superconductors, where the pressure required to clear the Cooper-pair condensate balances the pressures from the magnetic field and electron supercurrents.

The energy-pressure relations in both hadrons and vortices suggest that the confining pressure originates from their respective condensates: the gluon condensate arises from conformal symmetry breaking, while the superconducting condensate results from gauge symmetry breaking. In both cases, the confining pressure is equal to the negative of the energy density, in accordance with the Archimedes Principle.

We further note that this pressure-energy density relation also applies to the cosmological constant, which Einstein introduced through the metric term. Drawing an analogy with hadrons and superconducting vortices, we speculate that the conformal symmetry breaking in general relativity gives rise to a graviton condensate in the true vacuum, with the cosmological constant emerging as a manifestation of the Archimedes Principle.