quantum field theory In theoretical physics, quantum field theory (QFT) is a theoretical framework that combines Field theory (physics), field theory and the principle of relativity with ideas behind quantum mechanics. QFT is used in particle physics to construct phy ...

, the instanton fluid model is a model of Wick rotated Euclidean quantum chromodynamics. If we examine the path integral of the action, we find that it has infinitely many

local minima In mathematical analysis, the maximum and minimum of a function are, respectively, the greatest and least value taken by the function. Known generically as extremum, they may be defined either within a given range (the ''local'' or ''relative' ...

, corresponding to varying

instanton An instanton (or pseudoparticle) is a notion appearing in theoretical and mathematical physics. An instanton is a classical solution to equations of motion with a finite, non-zero action, either in quantum mechanics or in quantum field theory. M ...

numbers. It turns out that the dominant contribution to the path integral comes from configurations consisting of a pool of instantons and anti-instantons. The exponential suppression coming from the increased action is compensated by the increased phase space factor coming from all the instantons. In other words, the "Euclidean" free energy is minimized by a pool of instantons. We also know that in the presence of an instanton, left-handed quarks of each flavor will be produced and right-handed quarks annihilated. This evidently will have consequences to the chiral dynamics of the theory.

References

* Gauge theories Quantum chromodynamics {{quantum-stub