Before revision:  However, most of the existing deep learning-based methods either assume strong physics prior, or depend on specific initial and boundary conditions, or require data in dense regular grid making them inapt for modeling unknown PDEs from sparsely-observed data.
After revision:  However, most of the existing deep learning methods for modeling physical dynamics either focus on solving known PDEs or require data in dense regular grid making them inapt for modeling unknown PDEs from sparsely-observed data.