Confused by nonlocal models and relativity

[vanhees71]

The equation of state of strongly interacting matter, including in the regime valid for neutron stars/neutron-star merger physics is subject to vigorous current investigation. It's not yet fully understood.

 

[PeterDonis]

The equation of state of strongly interacting matter, including in the regime valid for neutron stars/neutron-star merger physics is subject to vigorous current investigation. It's not yet fully understood.

In the sense that we don't know its exact form, yes. But we know the range of possibilities well enough to know the range of possible maximum mass limits.