The number of papers on maximum force c^4/4G and similar limits in general relativity is growing. Last year there were
A. Jowsey et al, arXiv:2102.01831
V. Faraoni, Phys Rev D 103, 124010 (2021)
C. Schiller, Phys Rev D 104, 068501 (2021)
V. Faraoni, Phys Rev D 104, 068502 (2021)
C. Schiller...