We study the paralinearised weakly dispersive Burgers type equation:
βtβu+βxβ[Tuβu]βT2βxβuββu+βxββ£Dβ£Ξ±β1u=0,Β Ξ±β]1,2[, which contains the main non linear
"worst interaction" terms, i.e low-high interaction terms, of the usual weakly
dispersive Burgers type equation: βtβu+uβxβu+βxββ£Dβ£Ξ±β1u=0,Β Ξ±β]1,2[, with u0ββHs(D), where
D=TΒ orΒ R.
Through a paradifferential complex Cole-Hopf type gauge transform we
introduce for the study of the flow map regularity of Gravity-Capillary
equation, we prove a new a priori estimate in Hs(D) under the
control of β(1+β₯uβ₯Lxβββ)β₯uβ₯Wx2βΞ±,ββββLt1ββ, improving upon the
usual hyperbolic control β₯βxβuβ₯Lt1βLxβββ. Thus we eliminate the "standard" wave breaking
scenario in case of blow up as conjectured by J. C. Saut and C. Klein in their
numerical study of the dispersive Burgers equation.
For Ξ±β]2,3[ we show that we can completely conjugate the
paralinearised dispersive Burgers equation to a semi-linear equation of the
form: βtβu+βxββ£Dβ£Ξ±β1u=Rββ(u),Β Ξ±β]2,3[, where Rββ is a regularizing operator under the control of
β₯uβ₯LtββCβ2βΞ±ββ