2020/08/03 by Makram Hamouda, Hamouda, Makram, Mohamed Ali Hamza +1 · 2 citations
Engineering · Mathematics · #35B44 #35L71 #Advanced Mathematical Physics Problems #Analysis of PDEs (math.AP) #FOS: Mathematics #Navier-Stokes equation solutions #Stability and Controllability of Differential Equations
paper · pdf · doi:10.48550/arxiv.2008.02109
openalex publication_date 2020/08/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We consider in this article the damped wave equation, in the\n\scale-invariant case with combined two nonlinearities, which reads as\nfollows: \
d (E)
hspace1cm utt-
Deltaν+
frac
mu1+tut=|ut|p+|u|q,
quad
mboxin
RN
times[0,
infty),\n with small initial data. Compared to our previous work\n citeOur, we show in this article that the first hypothesis on the damping\ncoefficient \μ, namely \μ < \(N(q-1))/(2), can be removed, and the\nsecond one can be extended from (0, \μ_*/2) to (0, \μ_*) where \μ_*>0\nis solution of (q-1)\((N+\μ_*-1)p-2\) = 4. Indeed, owing to a\nbetter understanding of the influence of the damping term in the global\ndynamics of the solution, we think that this new interval for \μ describe\nbetter the threshold between the blow-up and the global existence regions.\nMoreover, taking advantage of the techniques employed in the problem (E), we\nalso improve the result in citeLT2,Palmieri in relationship with the Glassey\nconjecture for the solution of (E) but without the nonlinear term |u|q.\nMore precisely, we extend the blow-up region from p \∈ (1, pG(N+\σ)],\nwhere \σ is given by eqrefsigma below, to p \∈ (1, pG(N+\μ)]\ngiving thus a better estimate of the lifespan in this case.\n