A Higher Order Operator Splitting Method

AI Thread Summary
The discussion revolves around the application of the exponential form of solutions in higher-order operator splitting methods, particularly for deterministic parabolic equations. The user seeks clarification on how the exponential form can be applied when the operator "D" includes non-linear structures, specifically when x is dependent on t. They note that while the first-order expansion aligns with expectations, the second-order expansion fails to maintain consistency due to the presence of non-linear operators. The user expresses frustration over the lack of responses and requests additional resources or explanations to better understand the applicability of the exponential form in non-linear contexts. The inquiry highlights a gap in understanding the mathematical foundations of operator splitting methods when non-linearities are involved.
mertcan
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Hi, in the link https://www.researchgate.net/profile/Andrew_Sornborger/publication/220662120_Higher-order_operator_splitting_methods_for_deterministic_parabolic_equations/links/568ffaab08aec14fa557b85e/Higher-order-operator-splitting-methods-for-deterministic-parabolic-equations.pdf and equation 3 you will see the exponential form of the solution, also operator "D" includes non-linear operator structure written as ##\partial_x x##. Besides, I think in previous link x is dependent on t. I can understand that when operator "D" only consists of linear operators like ##\partial_x## then exponential form is consistent but I can not understand this situation is also possible when non-linear operators are included in "D". Could you provide me with mathematical demonstration to show that exponential form can be written also for non-linear operator structures??

When I expand exponential form of operator "D", I can see it is totally consistent with first order but when I come to second order expansion of operator "D" then it is not going well and not consistent contrary to link I shared. If "D" only included linear operators, it would be ok but here we have nonlinear operator, x depends on t so at the second order it can not be written as 1/2*D^2*##\Delta_t##
 
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Hi everyone it has been 3 days since I posted my that thread so still no response. please let me know if there is not understanble part in my question... I would be glad o provide additional infos
 
I do not know why I can not get responses but my question is so simple and humble: we can use exponential form of linear operators but can we use the same exponential form for NONLINEAR operators?? For more info can look at my post 1 ...
 
As it seems to me, I won't have responses but at least could you provide me with nice sources links files videos...?
 
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