Doubly nonlinear equation involving $p(x)$-homogeneous operators: local existence, uniqueness and global behaviour

Abstract: In this work, we investigate the qualitative properties as uniqueness, regularity and stabilization of the weak solution to the nonlinear parabolic problem involving general $p(x)$-homogeneous operators: \begin{equation*} \left{ \begin{alignedat}{2} {} \frac{q}{2q-1}\partial_t(u^{2q-1}) -\nabla.\, a(x, \nabla u) & {}= f(x,u) + h(t,x) u^{q-1} && \quad\mbox{ in } \, (0,T) \times \Omega; u & {}> 0 && \quad\mbox{ in }\, (0,T) \times \Omega ; u & {}= 0 && \quad\mbox{ on }\, (0,T) \times \partial\Omega; u(0,.)&{}= u_0 && \quad\ \mbox{in}\, \ \Omega. \end{alignedat} \right. \end{equation*} Thanks to the Picone's identity obtained in [10], we prove new results about comparison principles which yield a priori estimates, positivity and uniqueness of weak solutions.