Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
It is surjective for a $C^1$ boundary, see Demengel & DemengelDemengel & Demengel, section 3.3. Following the proof will probably answer your question.
It is surjective for a $C^1$ boundary, see Demengel & Demengel, section 3.3. Following the proof will probably answer your question.
