This is the second part in a four-paper sequence, which establishes the threshold conjecture and
the soliton bubbling vs. scattering dichotomy for the hyperbolic Yang–Mills equation in the
-dimensional
space-time. This paper provides the key gauge-dependent analysis of the hyperbolic
Yang–Mills equation.
We consider topologically trivial solutions in the caloric gauge, which was defined
in the first paper of the sequence using the Yang–Mills heat flow. In this gauge, we
establish a strong form of local well-posedness, where the time of existence is
bounded from below by the energy concentration scale. Moreover, we show that
regularity and dispersive properties of the solution persist as long as energy
dispersion is small. We also observe that fixed-time regularity (but not dispersive)
properties in the caloric gauge may be transferred to the temporal gauge without any
loss, proving as a consequence small-data global well-posedness in the temporal
gauge.
We use the results in this paper in subsequent papers to prove the sharp threshold
theorem in caloric gauge in the trivial topological class, and the dichotomy theorem
in arbitrary topological classes.
Keywords
hyperbolic Yang-Mills, energy critical, caloric gauge,
small energy dispersion, regularity, scattering