Abstract
In this paper, we deal with the identification of the space variable time derivative coefficient u in a degenerate fast diffusion differential inclusion. The function u is vanishing on a subset strictly included in the space domain Ω. This problem is approached as a control problem (P) with the control u. An approximating control problem (P ε ) is introduced and the existence of an optimal pair is proved. Under certain assumptions on the initial data, the control is found in W 2,m(Ω), with m>N, in an implicit variational form. Next, it is shown that a sequence of optimal pairs \((u_{\varepsilon }^{\ast },y_{\varepsilon }^{\ast })\) of (P ε ) converges as ε goes to 0 to a pair (u *,y *) which realizes the minimum in (P), and y * is the solution to the original state system.
An alternative approach to the control problem is done by considering two controls related between them by a certain elliptic problem. This approach leads to the determination of simpler conditions of optimality, but under an additional restriction upon the initial data of the direct problem.
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Marinoschi, G.: Functional Approach to Nonlinear Models of Water Flow in Soils. Mathematical Modelling: Theory and Applications, vol. 21. Springer, Dordrecht (2006)
Favini, A., Marinoschi, G.: Existence for a degenerate diffusion problem with a nonlinear operator. J. Evol. Equ. 7, 743–764 (2007)
Agmon, S., Douglis, A., Nirenberg, L.: Estimates near boundary for solutions of elliptic partial differential equations satisfying general boundary conditions. Commun. Pure Appl. Math. 12, 623–727 (1959)
Marinoschi, G.: A free boundary problem describing the saturated unsaturated flow in a porous medium. II. Existence of the free boundary in the 3-D case. Abstr. Appl. Anal. 8, 813–854 (2005)
Lions, J.L.: Quelques méthodes de résolution des problèmes aux limites non linéaires. Dunod, Paris (1969)
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Communicated by Ilio Galligani.
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Favini, A., Marinoschi, G. Identification of the Time Derivative Coefficient in a Fast Diffusion Degenerate Equation. J Optim Theory Appl 145, 249–269 (2010). https://doi.org/10.1007/s10957-009-9635-z
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DOI: https://doi.org/10.1007/s10957-009-9635-z