Rutvik Khedkar

Thank you for the paper. When extending this to the negative model I applied a very similar approach to the standard version. But after reading the positivity and boundedness discussion,...

> Sorry, but I didn't follow through with all your work. Did you also modify the Jacobian due to the new additional diffusion flux (actually diffusion and anti-diffusion fluxes)? yes,...

for the jacobians? i'll type them up and post them in a moment @YairMO heres the derivation. I've written it in the way it appears in the code. [jacobain_derivation_of_neg_model.pdf](https://github.com/user-attachments/files/20509067/jacobain_derivation_of_neg_model.pdf)

1. Thanks for the catch, it will be a small fix in the code since I use the chain rule for each expression. 2. The zeta function in eq.4 was...

Can you try it with a lower under relaxation factor? Maybe: `MAX_UPDATE_SST= 0.7`